diff --git a/src/calibre/ebooks/lrf/__init__.py b/src/calibre/ebooks/lrf/__init__.py
index 6c696b16ed..6be9e69e13 100644
--- a/src/calibre/ebooks/lrf/__init__.py
+++ b/src/calibre/ebooks/lrf/__init__.py
@@ -1,3 +1,5 @@
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
 """
diff --git a/src/calibre/ebooks/lrf/html/__init__.py b/src/calibre/ebooks/lrf/html/__init__.py
index 9e110971bf..cb4d4686eb 100644
--- a/src/calibre/ebooks/lrf/html/__init__.py
+++ b/src/calibre/ebooks/lrf/html/__init__.py
@@ -1,3 +1,5 @@
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
 """
diff --git a/src/calibre/ebooks/lrf/html/color_map.py b/src/calibre/ebooks/lrf/html/color_map.py
index 9c74c61018..ce4af2d71d 100644
--- a/src/calibre/ebooks/lrf/html/color_map.py
+++ b/src/calibre/ebooks/lrf/html/color_map.py
@@ -1,99 +1,101 @@
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
 
 import re
 
 NAME_MAP = {
-             u'aliceblue': u'#F0F8FF',
-             u'antiquewhite': u'#FAEBD7',
-             u'aqua': u'#00FFFF',
-             u'aquamarine': u'#7FFFD4',
-             u'azure': u'#F0FFFF',
-             u'beige': u'#F5F5DC',
-             u'bisque': u'#FFE4C4',
-             u'black': u'#000000',
-             u'blanchedalmond': u'#FFEBCD',
-             u'blue': u'#0000FF',
-             u'brown': u'#A52A2A',
-             u'burlywood': u'#DEB887',
-             u'cadetblue': u'#5F9EA0',
-             u'chartreuse': u'#7FFF00',
-             u'chocolate': u'#D2691E',
-             u'coral': u'#FF7F50',
-             u'crimson': u'#DC143C',
-             u'cyan': u'#00FFFF',
-             u'darkblue': u'#00008B',
-             u'darkgoldenrod': u'#B8860B',
-             u'darkgreen': u'#006400',
-             u'darkkhaki': u'#BDB76B',
-             u'darkmagenta': u'#8B008B',
-             u'darkolivegreen': u'#556B2F',
-             u'darkorange': u'#FF8C00',
-             u'darkorchid': u'#9932CC',
-             u'darkred': u'#8B0000',
-             u'darksalmon': u'#E9967A',
-             u'darkslateblue': u'#483D8B',
-             u'darkslategrey': u'#2F4F4F',
-             u'darkviolet': u'#9400D3',
-             u'deeppink': u'#FF1493',
-             u'dodgerblue': u'#1E90FF',
-             u'firebrick': u'#B22222',
-             u'floralwhite': u'#FFFAF0',
-             u'forestgreen': u'#228B22',
-             u'fuchsia': u'#FF00FF',
-             u'gainsboro': u'#DCDCDC',
-             u'ghostwhite': u'#F8F8FF',
-             u'gold': u'#FFD700',
-             u'goldenrod': u'#DAA520',
-             u'indianred ': u'#CD5C5C',
-             u'indigo  ': u'#4B0082',
-             u'khaki': u'#F0E68C',
-             u'lavenderblush': u'#FFF0F5',
-             u'lawngreen': u'#7CFC00',
-             u'lightblue': u'#ADD8E6',
-             u'lightcoral': u'#F08080',
-             u'lightgoldenrodyellow': u'#FAFAD2',
-             u'lightgray': u'#D3D3D3',
-             u'lightgrey': u'#D3D3D3',
-             u'lightskyblue': u'#87CEFA',
-             u'lightslategrey': u'#778899',
-             u'lightsteelblue': u'#B0C4DE',
-             u'lime': u'#87CEFA',
-             u'linen': u'#FAF0E6',
-             u'magenta': u'#FF00FF',
-             u'maroon': u'#800000',
-             u'mediumaquamarine': u'#66CDAA',
-             u'mediumblue': u'#0000CD',
-             u'mediumorchid': u'#BA55D3',
-             u'mediumpurple': u'#9370D8',
-             u'mediumseagreen': u'#3CB371',
-             u'mediumslateblue': u'#7B68EE',
-             u'midnightblue': u'#191970',
-             u'moccasin': u'#FFE4B5',
-             u'navajowhite': u'#FFDEAD',
-             u'navy': u'#000080',
-             u'oldlace': u'#FDF5E6',
-             u'olive': u'#808000',
-             u'orange': u'#FFA500',
-             u'orangered': u'#FF4500',
-             u'orchid': u'#DA70D6',
-             u'paleturquoise': u'#AFEEEE',
-             u'papayawhip': u'#FFEFD5',
-             u'peachpuff': u'#FFDAB9',
-             u'powderblue': u'#B0E0E6',
-             u'rosybrown': u'#BC8F8F',
-             u'royalblue': u'#4169E1',
-             u'saddlebrown': u'#8B4513',
-             u'sandybrown': u'#8B4513',
-             u'seashell': u'#FFF5EE',
-             u'sienna': u'#A0522D',
-             u'silver': u'#C0C0C0',
-             u'skyblue': u'#87CEEB',
-             u'slategrey': u'#708090',
-             u'snow': u'#FFFAFA',
-             u'springgreen': u'#00FF7F',
-             u'violet': u'#EE82EE',
-             u'yellowgreen': u'#9ACD32'
+             'aliceblue': '#F0F8FF',
+             'antiquewhite': '#FAEBD7',
+             'aqua': '#00FFFF',
+             'aquamarine': '#7FFFD4',
+             'azure': '#F0FFFF',
+             'beige': '#F5F5DC',
+             'bisque': '#FFE4C4',
+             'black': '#000000',
+             'blanchedalmond': '#FFEBCD',
+             'blue': '#0000FF',
+             'brown': '#A52A2A',
+             'burlywood': '#DEB887',
+             'cadetblue': '#5F9EA0',
+             'chartreuse': '#7FFF00',
+             'chocolate': '#D2691E',
+             'coral': '#FF7F50',
+             'crimson': '#DC143C',
+             'cyan': '#00FFFF',
+             'darkblue': '#00008B',
+             'darkgoldenrod': '#B8860B',
+             'darkgreen': '#006400',
+             'darkkhaki': '#BDB76B',
+             'darkmagenta': '#8B008B',
+             'darkolivegreen': '#556B2F',
+             'darkorange': '#FF8C00',
+             'darkorchid': '#9932CC',
+             'darkred': '#8B0000',
+             'darksalmon': '#E9967A',
+             'darkslateblue': '#483D8B',
+             'darkslategrey': '#2F4F4F',
+             'darkviolet': '#9400D3',
+             'deeppink': '#FF1493',
+             'dodgerblue': '#1E90FF',
+             'firebrick': '#B22222',
+             'floralwhite': '#FFFAF0',
+             'forestgreen': '#228B22',
+             'fuchsia': '#FF00FF',
+             'gainsboro': '#DCDCDC',
+             'ghostwhite': '#F8F8FF',
+             'gold': '#FFD700',
+             'goldenrod': '#DAA520',
+             'indianred ': '#CD5C5C',
+             'indigo  ': '#4B0082',
+             'khaki': '#F0E68C',
+             'lavenderblush': '#FFF0F5',
+             'lawngreen': '#7CFC00',
+             'lightblue': '#ADD8E6',
+             'lightcoral': '#F08080',
+             'lightgoldenrodyellow': '#FAFAD2',
+             'lightgray': '#D3D3D3',
+             'lightgrey': '#D3D3D3',
+             'lightskyblue': '#87CEFA',
+             'lightslategrey': '#778899',
+             'lightsteelblue': '#B0C4DE',
+             'lime': '#87CEFA',
+             'linen': '#FAF0E6',
+             'magenta': '#FF00FF',
+             'maroon': '#800000',
+             'mediumaquamarine': '#66CDAA',
+             'mediumblue': '#0000CD',
+             'mediumorchid': '#BA55D3',
+             'mediumpurple': '#9370D8',
+             'mediumseagreen': '#3CB371',
+             'mediumslateblue': '#7B68EE',
+             'midnightblue': '#191970',
+             'moccasin': '#FFE4B5',
+             'navajowhite': '#FFDEAD',
+             'navy': '#000080',
+             'oldlace': '#FDF5E6',
+             'olive': '#808000',
+             'orange': '#FFA500',
+             'orangered': '#FF4500',
+             'orchid': '#DA70D6',
+             'paleturquoise': '#AFEEEE',
+             'papayawhip': '#FFEFD5',
+             'peachpuff': '#FFDAB9',
+             'powderblue': '#B0E0E6',
+             'rosybrown': '#BC8F8F',
+             'royalblue': '#4169E1',
+             'saddlebrown': '#8B4513',
+             'sandybrown': '#8B4513',
+             'seashell': '#FFF5EE',
+             'sienna': '#A0522D',
+             'silver': '#C0C0C0',
+             'skyblue': '#87CEEB',
+             'slategrey': '#708090',
+             'snow': '#FFFAFA',
+             'springgreen': '#00FF7F',
+             'violet': '#EE82EE',
+             'yellowgreen': '#9ACD32'
             }
 
 hex_pat = re.compile(r'#(\d{2})(\d{2})(\d{2})')
diff --git a/src/calibre/ebooks/lrf/html/convert_from.py b/src/calibre/ebooks/lrf/html/convert_from.py
index 41ec5cb6ce..be4feb2aeb 100644
--- a/src/calibre/ebooks/lrf/html/convert_from.py
+++ b/src/calibre/ebooks/lrf/html/convert_from.py
@@ -1,4 +1,5 @@
-from __future__ import print_function
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
 """
@@ -106,7 +107,7 @@ class HTMLConverter(object):
                                     re.IGNORECASE), lambda m: '<br />'),
 
                         # Replace entities
-                        (re.compile(u'&(\\S+?);'), partial(entity_to_unicode,
+                        (re.compile(r'&(\S+?);'), partial(entity_to_unicode,
                                                            exceptions=['lt', 'gt', 'amp', 'quot'])),
                         # Remove comments from within style tags as they can mess up BeatifulSoup
                         (re.compile(r'(<style.*?</style>)', re.IGNORECASE|re.DOTALL),
@@ -397,7 +398,7 @@ class HTMLConverter(object):
     def parse_css(self, style):
         """
         Parse the contents of a <style> tag or .css file.
-        @param style: C{str(style)} should be the CSS to parse.
+        @param style: C{unicode_type(style)} should be the CSS to parse.
         @return: A dictionary with one entry per selector where the key is the
         selector name and the value is a dictionary of properties
         """
@@ -789,7 +790,7 @@ class HTMLConverter(object):
             src = src.lstrip()
             f = src[0]
             next = 1
-            if f in ("'", '"', u'\u201c', u'\u2018', u'\u201d', u'\u2019'):
+            if f in ("'", '"', '\u201c', '\u2018', '\u201d', '\u2019'):
                 if len(src) >= 2:
                     next = 2
                     f = src[:2]
@@ -805,14 +806,14 @@ class HTMLConverter(object):
 
         def append_text(src):
             fp, key, variant = self.font_properties(css)
-            for x, y in [(u'\xad', ''), (u'\xa0', ' '), (u'\ufb00', 'ff'), (u'\ufb01', 'fi'), (u'\ufb02', 'fl'), (u'\ufb03', 'ffi'), (u'\ufb04', 'ffl')]:
+            for x, y in [('\xad', ''), ('\xa0', ' '), ('\ufb00', 'ff'), ('\ufb01', 'fi'), ('\ufb02', 'fl'), ('\ufb03', 'ffi'), ('\ufb04', 'ffl')]:
                 src = src.replace(x, y)
 
             valigner = lambda x: x
             if 'vertical-align' in css:
                 valign = css['vertical-align']
                 if valign in ('sup', 'super', 'sub'):
-                    fp['fontsize'] = int(int(fp['fontsize']) * 5 / 3.0)
+                    fp['fontsize'] = int(fp['fontsize']) * 5 // 3
                     valigner = Sub if valign == 'sub' else Sup
             normal_font_size = int(fp['fontsize'])
 
@@ -864,12 +865,12 @@ class HTMLConverter(object):
 
         if collapse_whitespace:
             src = re.sub(r'\s{1,}', ' ', src)
-            if self.stripped_space and len(src) == len(src.lstrip(u' \n\r\t')):
+            if self.stripped_space and len(src) == len(src.lstrip(' \n\r\t')):
                 src = self.stripped_space + src
-            src, orig = src.rstrip(u' \n\r\t'), src
+            src, orig = src.rstrip(' \n\r\t'), src
             self.stripped_space = orig[len(src):]
-            if len(self.previous_text) != len(self.previous_text.rstrip(u' \n\r\t')):
-                src = src.lstrip(u' \n\r\t')
+            if len(self.previous_text) != len(self.previous_text.rstrip(' \n\r\t')):
+                src = src.lstrip(' \n\r\t')
             if len(src):
                 self.previous_text = src
                 append_text(src)
@@ -971,8 +972,8 @@ class HTMLConverter(object):
                                xsize=width, ysize=height)
             line_height = (int(self.current_block.textStyle.attrs['baselineskip']) +
                             int(self.current_block.textStyle.attrs['linespace']))//10
-            line_height *= self.profile.dpi/72.
-            lines = int(ceil(float(height)/line_height))
+            line_height *= self.profile.dpi/72
+            lines = int(ceil(height/line_height))
             dc = DropCaps(lines)
             dc.append(Plot(im, xsize=ceil(width*factor), ysize=ceil(height*factor)))
             self.current_para.append(dc)
@@ -1011,10 +1012,10 @@ class HTMLConverter(object):
 
         self.process_alignment(tag_css)
 
-        if max(width, height) <= min(pwidth, pheight)/5.:
+        if max(width, height) <= min(pwidth, pheight)/5:
             self.current_para.append(Plot(im, xsize=ceil(width*factor),
                                           ysize=ceil(height*factor)))
-        elif height <= int(floor((2/3.)*pheight)):
+        elif height <= int(floor((2/3)*pheight)):
             pb = self.current_block
             self.end_current_para()
             self.process_alignment(tag_css)
@@ -1032,7 +1033,7 @@ class HTMLConverter(object):
                 self.current_page.contents[0:1] = []
             self.current_page.append(Canvas(width=pwidth,
                                             height=height))
-            left = int(floor((pwidth - width)/2.))
+            left = int(floor((pwidth - width)/2))
             self.current_page.contents[-1].put_object(
                             ImageBlock(self.images[path], xsize=width,
                                        ysize=height, x1=width, y1=height,
@@ -1083,7 +1084,7 @@ class HTMLConverter(object):
 
         s1, s2 = get('margin'), get('padding')
 
-        bl = str(self.current_block.blockStyle.attrs['blockwidth'])+'px'
+        bl = unicode_type(self.current_block.blockStyle.attrs['blockwidth'])+'px'
 
         def set(default, one, two):
             fval = None
@@ -1113,7 +1114,7 @@ class HTMLConverter(object):
             val /= 2.
             ans['sidemargin'] = int(val)
         if 2*int(ans['sidemargin']) >= factor*int(self.current_block.blockStyle.attrs['blockwidth']):
-            ans['sidemargin'] = int((factor*int(self.current_block.blockStyle.attrs['blockwidth']))/2.)
+            ans['sidemargin'] = (factor*int(self.current_block.blockStyle.attrs['blockwidth'])) // 2
 
         for prop in ('topskip', 'footskip', 'sidemargin'):
             if isinstance(ans[prop], string_or_bytes):
@@ -1212,7 +1213,7 @@ class HTMLConverter(object):
                     ans = 120
             if ans is not None:
                 ans += int(self.font_delta * 20)
-                ans = str(ans)
+                ans = unicode_type(ans)
             return ans
 
         family, weight, style, variant = 'serif', 'normal', 'normal', None
@@ -1268,7 +1269,7 @@ class HTMLConverter(object):
 
         fs = int(t['fontsize'])
         if fs > 120:
-            t['wordspace'] = int(fs/4.)
+            t['wordspace'] = fs // 4
         t['baselineskip'] = fs + 20
         return t, key, variant
 
@@ -1290,27 +1291,27 @@ class HTMLConverter(object):
             unit = float(m.group(1))
             if m.group(2) == '%':
                 normal = self.unit_convert(base_length)
-                result = (unit/100.0) * normal
+                result = (unit/100) * normal
             elif m.group(2) == 'px':
                 result = unit
             elif m.group(2) == 'in':
                 result = unit * dpi
             elif m.group(2) == 'pt':
-                result = unit * dpi/72.
+                result = unit * dpi/72
             elif m.group(2) == 'dpt':
-                result = unit * dpi/720.
+                result = unit * dpi/720
             elif m.group(2) == 'em':
                 normal = self.unit_convert(base_length)
                 result = unit * normal
             elif m.group(2) == 'pc':
-                result = unit * (dpi/72.) * 12
+                result = unit * (dpi/72) * 12
             elif m.group(2) == 'mm':
                 result = unit * 0.04 * (dpi)
             elif m.group(2) == 'cm':
                 result = unit * 0.4 * (dpi)
         if result is not None:
             if pts:
-                result = int(round(result * (720./dpi)))
+                result = int(round(result * (720/dpi)))
             else:
                 result = int(round(result))
         return result
@@ -1318,7 +1319,7 @@ class HTMLConverter(object):
     def text_properties(self, tag_css):
         indent = self.book.defaultTextStyle.attrs['parindent']
         if 'text-indent' in tag_css:
-            bl = str(self.current_block.blockStyle.attrs['blockwidth'])+'px'
+            bl = unicode_type(self.current_block.blockStyle.attrs['blockwidth'])+'px'
             if 'em' in tag_css['text-indent']:
                 bl = '10pt'
             indent = self.unit_convert(unicode_type(tag_css['text-indent']), pts=True, base_length=bl)
@@ -1349,12 +1350,12 @@ class HTMLConverter(object):
         ''' Ensure padding and text-indent properties are respected '''
         text_properties = self.text_properties(tag_css)
         block_properties = self.block_properties(tag_css)
-        indent = (float(text_properties['parindent'])/10) * (self.profile.dpi/72.)
+        indent = (float(text_properties['parindent'])//10) * (self.profile.dpi/72)
         margin = float(block_properties['sidemargin'])
         # Since we're flattening the block structure, we need to ensure that text
         # doesn't go off the left edge of the screen
         if indent < 0 and margin + indent < 0:
-            text_properties['parindent'] = int(-margin * (72./self.profile.dpi) * 10)
+            text_properties['parindent'] = int(-margin * (72/self.profile.dpi) * 10)
 
         align = self.get_alignment(tag_css)
 
@@ -1515,7 +1516,7 @@ class HTMLConverter(object):
                     elif not urlparse(tag['src'])[0]:
                         self.log.warn('Could not find image: '+tag['src'])
                 else:
-                    self.log.debug("Failed to process: %s"%str(tag))
+                    self.log.debug("Failed to process: %s"%unicode_type(tag))
             elif tagname in ['style', 'link']:
                 ncss, npcss = {}, {}
                 if tagname == 'style':
@@ -1609,7 +1610,7 @@ class HTMLConverter(object):
                             in_ol = parent.name.lower() == 'ol'
                             break
                         parent = parent.parent
-                    prepend = str(self.list_counter)+'. ' if in_ol else u'\u2022' + ' '
+                    prepend = unicode_type(self.list_counter)+'. ' if in_ol else '\u2022' + ' '
                     self.current_para.append(Span(prepend))
                     self.process_children(tag, tag_css, tag_pseudo_css)
                     if in_ol:
@@ -1652,7 +1653,7 @@ class HTMLConverter(object):
 
                 if (self.anchor_ids and tag.has_attr('id')) or (self.book_designer and tag.get('class') in ('title', ['title'])):
                     if not tag.has_attr('id'):
-                        tag['id'] = __appname__+'_id_'+str(self.id_counter)
+                        tag['id'] = __appname__+'_id_'+unicode_type(self.id_counter)
                         self.id_counter += 1
 
                     tkey = self.target_prefix+tag['id']
@@ -1781,7 +1782,7 @@ class HTMLConverter(object):
             else:
                 if xpos > 65535:
                     xpos = 65535
-                canvases[-1].put_object(block, xpos + int(delta/2.), ypos)
+                canvases[-1].put_object(block, xpos + delta//2, ypos)
 
         for canvas in canvases:
             self.current_page.append(canvas)
@@ -1819,7 +1820,7 @@ def process_file(path, options, logger):
                               options.profile.screen_height - options.profile.fudge
             width, height = im.size
             if width < pwidth:
-                corrf = float(pwidth)/width
+                corrf = pwidth/width
                 width, height = pwidth, int(corrf*height)
 
             scaled, width, height = fit_image(width, height, pwidth, pheight)
diff --git a/src/calibre/ebooks/lrf/html/table.py b/src/calibre/ebooks/lrf/html/table.py
index 43b260407e..8caa576749 100644
--- a/src/calibre/ebooks/lrf/html/table.py
+++ b/src/calibre/ebooks/lrf/html/table.py
@@ -1,4 +1,5 @@
-from __future__ import print_function
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
 import math, sys, re, numbers
@@ -125,7 +126,7 @@ class Cell(object):
 
     def pts_to_pixels(self, pts):
         pts = int(pts)
-        return ceil((float(self.conv.profile.dpi)/72.)*(pts/10.))
+        return ceil((float(self.conv.profile.dpi)/72)*(pts/10))
 
     def minimum_width(self):
         return max([self.minimum_tb_width(tb) for tb in self.text_blocks])
@@ -328,15 +329,15 @@ class Table(object):
         min_widths = [self.minimum_width(i)+10 for i in range(cols)]
         for i in range(len(widths)):
             wp = self.width_percent(i)
-            if wp >= 0.:
-                widths[i] = max(min_widths[i], ceil((wp/100.) * (maxwidth - (cols-1)*self.colpad)))
+            if wp >= 0:
+                widths[i] = max(min_widths[i], ceil((wp/100) * (maxwidth - (cols-1)*self.colpad)))
 
         itercount = 0
 
         while sum(widths) > maxwidth-((len(widths)-1)*self.colpad) and itercount < 100:
             for i in range(cols):
-                widths[i] = ceil((95./100.)*widths[i]) if \
-                    ceil((95./100.)*widths[i]) >= min_widths[i] else widths[i]
+                widths[i] = ceil((95/100)*widths[i]) if \
+                    ceil((95/100)*widths[i]) >= min_widths[i] else widths[i]
             itercount += 1
 
         return [i+self.colpad for i in widths]
diff --git a/src/calibre/ebooks/lrf/html/table_as_image.py b/src/calibre/ebooks/lrf/html/table_as_image.py
index 22aca5b0f8..9606e49476 100644
--- a/src/calibre/ebooks/lrf/html/table_as_image.py
+++ b/src/calibre/ebooks/lrf/html/table_as_image.py
@@ -1,4 +1,6 @@
 #!/usr/bin/env  python2
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2008, Kovid Goyal kovid@kovidgoyal.net'
 __docformat__ = 'restructuredtext en'
@@ -73,7 +75,7 @@ def render_table(soup, table, css, base_dir, width, height, dpi, factor=1.0):
     style = ''
     for key, val in css.items():
         style += key + ':%s;'%val
-    html = u'''\
+    html = '''\
 <html>
     <head>
         %s
diff --git a/src/calibre/ebooks/lrf/input.py b/src/calibre/ebooks/lrf/input.py
index 77d43335da..f678fcbe32 100644
--- a/src/calibre/ebooks/lrf/input.py
+++ b/src/calibre/ebooks/lrf/input.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
-from __future__ import with_statement
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2009, Kovid Goyal <kovid@kovidgoyal.net>'
@@ -12,7 +12,7 @@ from copy import deepcopy, copy
 from lxml import etree
 
 from calibre import guess_type
-from polyglot.builtins import as_bytes, map
+from polyglot.builtins import as_bytes, map, unicode_type
 
 
 class Canvas(etree.XSLTExtension):
@@ -70,9 +70,9 @@ class Canvas(etree.XSLTExtension):
         height = self.styles.to_num(block.get("ysize", None))
         img = div.makeelement('img')
         if width is not None:
-            img.set('width', str(int(width)))
+            img.set('width', unicode_type(int(width)))
         if height is not None:
-            img.set('height', str(int(height)))
+            img.set('height', unicode_type(int(height)))
         ref = block.get('refstream', None)
         if ref is not None:
             imstr = self.doc.xpath('//ImageStream[@objid="%s"]'%ref)
@@ -263,13 +263,13 @@ class TextBlock(etree.XSLTExtension):
                 a.set('href', self.char_button_map[oid])
             self.process_container(child, a)
         elif child.tag == 'Plot':
-            xsize = self.styles.to_num(child.get('xsize', None), 166./720)
-            ysize = self.styles.to_num(child.get('ysize', None), 166./720)
+            xsize = self.styles.to_num(child.get('xsize', None), 166/720)
+            ysize = self.styles.to_num(child.get('ysize', None), 166/720)
             img = self.root.makeelement('img')
             if xsize is not None:
-                img.set('width', str(int(xsize)))
+                img.set('width', unicode_type(int(xsize)))
             if ysize is not None:
-                img.set('height', str(int(ysize)))
+                img.set('height', unicode_type(int(ysize)))
             ro = child.get('refobj', None)
             if ro in self.plot_map:
                 img.set('src', self.plot_map[ro])
@@ -320,8 +320,7 @@ class Styles(etree.XSLTExtension):
 
     def px_to_pt(self, px):
         try:
-            px = float(px)
-            return px * 72./166.
+            return px * 72/166
         except:
             return None
 
diff --git a/src/calibre/ebooks/lrf/lrs/__init__.py b/src/calibre/ebooks/lrf/lrs/__init__.py
index 0983eee411..205df68b90 100644
--- a/src/calibre/ebooks/lrf/lrs/__init__.py
+++ b/src/calibre/ebooks/lrf/lrs/__init__.py
@@ -1,6 +1,5 @@
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
 ''''''
-
-
-
diff --git a/src/calibre/ebooks/lrf/lrs/convert_from.py b/src/calibre/ebooks/lrf/lrs/convert_from.py
index f5ac2da0bf..1350addb60 100644
--- a/src/calibre/ebooks/lrf/lrs/convert_from.py
+++ b/src/calibre/ebooks/lrf/lrs/convert_from.py
@@ -1,4 +1,5 @@
-from __future__ import print_function
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
 '''
@@ -21,7 +22,7 @@ from calibre.ebooks.lrf.pylrs.pylrs import (
     TextStyle
 )
 from calibre.utils.config import OptionParser
-from polyglot.builtins import string_or_bytes
+from polyglot.builtins import string_or_bytes, unicode_type
 
 
 class LrsParser(object):
@@ -54,7 +55,7 @@ class LrsParser(object):
         for key, val in tag.attrs:
             if key in exclude:
                 continue
-            result[str(key)] = val
+            result[unicode_type(key)] = val
         return result
 
     def text_tag_to_element(self, tag):
diff --git a/src/calibre/ebooks/lrf/objects.py b/src/calibre/ebooks/lrf/objects.py
index b8b276d3a4..59fc725c0c 100644
--- a/src/calibre/ebooks/lrf/objects.py
+++ b/src/calibre/ebooks/lrf/objects.py
@@ -7,7 +7,7 @@ import struct, array, zlib, io, collections, re
 from calibre.ebooks.lrf import LRFParseError, PRS500_PROFILE
 from calibre import entity_to_unicode, prepare_string_for_xml
 from calibre.ebooks.lrf.tags import Tag
-from polyglot.builtins import is_py3, unicode_type, string_or_bytes
+from polyglot.builtins import is_py3, unicode_type
 
 ruby_tags = {
         0xF575: ['rubyAlignAndAdjust', 'W'],
@@ -83,7 +83,7 @@ class LRFObject(object):
             if h[1] != '' and h[0] != '':
                 setattr(self, h[0], val)
         else:
-            raise LRFParseError("Unknown tag in %s: %s" % (self.__class__.__name__, str(tag)))
+            raise LRFParseError("Unknown tag in %s: %s" % (self.__class__.__name__, unicode_type(tag)))
 
     def __iter__(self):
         for i in range(0):
@@ -121,7 +121,7 @@ class LRFContentObject(LRFObject):
     def handle_tag(self, tag):
         if tag.id in self.tag_map:
             action = self.tag_map[tag.id]
-            if isinstance(action, string_or_bytes):
+            if isinstance(action, unicode_type):
                 func, args = action, ()
             else:
                 func, args = action[0], (action[1],)
@@ -325,7 +325,7 @@ class Wait(EmptyPageElement):
 
 class Locate(EmptyPageElement):
 
-    pos_map = {1:'bottomleft', 2:'bottomright',3:'topright',4:'topleft', 5:'base'}
+    pos_map = {1:'bottomleft', 2:'bottomright', 3:'topright', 4:'topleft', 5:'base'}
 
     def __init__(self, pos):
         self.pos = self.pos_map[pos]
@@ -355,7 +355,7 @@ class Page(LRFStream):
         0xF503: ['style_id', 'D'],
         0xF50B: ['obj_list', 'P'],
         0xF571: ['', ''],
-        0xF57C: ['parent_page_tree','D'],
+        0xF57C: ['parent_page_tree', 'D'],
       }
     tag_map.update(PageAttr.tag_map)
     tag_map.update(LRFStream.tag_map)
@@ -377,9 +377,9 @@ class Page(LRFStream):
            0xF5D6: 'sound_stop',
           }
 
-        def __init__(self, bytes, objects):
+        def __init__(self, byts, objects):
             self.in_blockspace = False
-            LRFContentObject.__init__(self, bytes, objects)
+            LRFContentObject.__init__(self, byts, objects)
 
         def link(self, tag):
             self.close_blockspace()
@@ -524,7 +524,7 @@ class TextCSS(object):
 
         fs = getattr(obj, 'fontsize', None)
         if fs is not None:
-            ans += item('font-size: %fpt;'%(int(fs)/10.))
+            ans += item('font-size: %fpt;'%(int(fs)/10))
         fw = getattr(obj, 'fontweight', None)
         if fw is not None:
             ans += item('font-weight: %s;'%('bold' if int(fw) >= 700 else 'normal'))
@@ -546,10 +546,10 @@ class TextCSS(object):
             ans += item('text-align: %s;'%al)
         lh = getattr(obj, 'linespace', None)
         if lh is not None:
-            ans += item('text-align: %fpt;'%(int(lh)/10.))
+            ans += item('text-align: %fpt;'%(int(lh)/10))
         pi = getattr(obj, 'parindent', None)
         if pi is not None:
-            ans += item('text-indent: %fpt;'%(int(pi)/10.))
+            ans += item('text-indent: %fpt;'%(int(pi)/10))
 
         return ans
 
@@ -880,7 +880,7 @@ class Text(LRFStream):
                 self.add_text(stream.read(tag.word))
             elif tag.id in self.__class__.text_tags:  # A Text tag
                 action = self.__class__.text_tags[tag.id]
-                if isinstance(action, string_or_bytes):
+                if isinstance(action, unicode_type):
                     getattr(self, action)(tag, stream)
                 else:
                     getattr(self, action[0])(tag, action[1])
@@ -904,7 +904,7 @@ class Text(LRFStream):
         s = ''
         open_containers = collections.deque()
         for c in self.content:
-            if isinstance(c, string_or_bytes):
+            if isinstance(c, unicode_type):
                 s += prepare_string_for_xml(c).replace('\0', '')
             elif c is None:
                 if open_containers:
@@ -930,7 +930,7 @@ class Text(LRFStream):
         open_containers = collections.deque()
         in_p = False
         for c in self.content:
-            if isinstance(c, string_or_bytes):
+            if isinstance(c, unicode_type):
                 s += c
             elif c is None:
                 if c.name == 'P':
diff --git a/src/calibre/ebooks/lrf/pylrs/__init__.py b/src/calibre/ebooks/lrf/pylrs/__init__.py
index f4d0439228..72b8c8d968 100644
--- a/src/calibre/ebooks/lrf/pylrs/__init__.py
+++ b/src/calibre/ebooks/lrf/pylrs/__init__.py
@@ -1,3 +1,5 @@
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 """
 This package contains code to generate ebooks in the SONY LRS/F format. It was
 originally developed by Mike Higgins and has been extended and modified by Kovid
diff --git a/src/calibre/ebooks/lrf/pylrs/elements.py b/src/calibre/ebooks/lrf/pylrs/elements.py
index f61f79b15f..fa2b8a0b21 100644
--- a/src/calibre/ebooks/lrf/pylrs/elements.py
+++ b/src/calibre/ebooks/lrf/pylrs/elements.py
@@ -1,3 +1,5 @@
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 """ elements.py -- replacements and helpers for ElementTree """
 
 from polyglot.builtins import unicode_type, string_or_bytes
@@ -14,7 +16,7 @@ class ElementWriter(object):
         self.outputEncodingName = outputEncodingName
 
     def _encodeCdata(self, rawText):
-        if type(rawText) is str:
+        if isinstance(rawText, bytes):
             rawText = rawText.decode(self.sourceEncoding)
 
         text = rawText.replace("&", "&amp;")
@@ -23,20 +25,20 @@ class ElementWriter(object):
         return text
 
     def _writeAttribute(self, f, name, value):
-        f.write(u' %s="' % unicode_type(name))
+        f.write(' %s="' % unicode_type(name))
         if not isinstance(value, string_or_bytes):
             value = unicode_type(value)
         value = self._encodeCdata(value)
         value = value.replace('"', '&quot;')
         f.write(value)
-        f.write(u'"')
+        f.write('"')
 
     def _writeText(self, f, rawText):
         text = self._encodeCdata(rawText)
         f.write(text)
 
     def _write(self, f, e):
-        f.write(u'<' + unicode_type(e.tag))
+        f.write('<' + unicode_type(e.tag))
 
         attributes = e.items()
         attributes.sort()
@@ -44,7 +46,7 @@ class ElementWriter(object):
             self._writeAttribute(f, name, value)
 
         if e.text is not None or len(e) > 0:
-            f.write(u'>')
+            f.write('>')
 
             if e.text:
                 self._writeText(f, e.text)
@@ -52,11 +54,11 @@ class ElementWriter(object):
             for e2 in e:
                 self._write(f, e2)
 
-            f.write(u'</%s>' % e.tag)
+            f.write('</%s>' % e.tag)
         else:
             if self.spaceBeforeClose:
                 f.write(' ')
-            f.write(u'/>')
+            f.write('/>')
 
         if e.tail is not None:
             self._writeText(f, e.tail)
@@ -67,10 +69,10 @@ class ElementWriter(object):
         buffer = []
         x.write = buffer.append
         self.write(x)
-        return u''.join(buffer)
+        return ''.join(buffer)
 
     def write(self, f):
         if self.header:
-            f.write(u'<?xml version="1.0" encoding="%s"?>\n' % self.outputEncodingName)
+            f.write('<?xml version="1.0" encoding="%s"?>\n' % self.outputEncodingName)
 
         self._write(f, self.e)
diff --git a/src/calibre/ebooks/lrf/pylrs/pylrf.py b/src/calibre/ebooks/lrf/pylrs/pylrf.py
index f99eea6be9..21bdb18afc 100644
--- a/src/calibre/ebooks/lrf/pylrs/pylrf.py
+++ b/src/calibre/ebooks/lrf/pylrs/pylrf.py
@@ -1,4 +1,6 @@
 #!/usr/bin/env python2
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 """
     pylrf.py -- very low level interface to create lrf files.  See pylrs for
     higher level interface that can use this module to render books to lrf.
@@ -10,7 +12,7 @@ import codecs
 import os
 
 from .pylrfopt import tagListOptimizer
-from polyglot.builtins import iteritems, string_or_bytes
+from polyglot.builtins import iteritems, string_or_bytes, unicode_type
 
 PYLRF_VERSION = "1.0"
 
@@ -83,7 +85,7 @@ def writeWord(f, word):
     if int(word) > 65535:
         raise LrfError('Cannot encode a number greater than 65535 in a word.')
     if int(word) < 0:
-        raise LrfError('Cannot encode a number < 0 in a word: '+str(word))
+        raise LrfError('Cannot encode a number < 0 in a word: '+unicode_type(word))
     f.write(struct.pack("<H", int(word)))
 
 
@@ -510,7 +512,7 @@ class LrfObject(object):
             raise LrfError("object name %s not recognized" % name)
 
     def __str__(self):
-        return 'LRFObject: ' + self.name + ", " + str(self.objId)
+        return 'LRFObject: ' + self.name + ", " + unicode_type(self.objId)
 
     def appendLrfTag(self, tag):
         self.tags.append(tag)
diff --git a/src/calibre/ebooks/lrf/pylrs/pylrfopt.py b/src/calibre/ebooks/lrf/pylrs/pylrfopt.py
index 6f0e9d97da..35b02c1971 100644
--- a/src/calibre/ebooks/lrf/pylrs/pylrfopt.py
+++ b/src/calibre/ebooks/lrf/pylrs/pylrfopt.py
@@ -1,3 +1,5 @@
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 def _optimize(tagList, tagName, conversion):
     # copy the tag of interest plus any text
     newTagList = []
@@ -39,5 +41,3 @@ def tagListOptimizer(tagList):
     _optimize(tagList, "fontsize", int)
     _optimize(tagList, "fontweight", int)
     return oldSize - len(tagList)
-
-
diff --git a/src/calibre/ebooks/lrf/pylrs/pylrs.py b/src/calibre/ebooks/lrf/pylrs/pylrs.py
index 207de6e6b7..55a27960cd 100644
--- a/src/calibre/ebooks/lrf/pylrs/pylrs.py
+++ b/src/calibre/ebooks/lrf/pylrs/pylrs.py
@@ -1,4 +1,5 @@
-from __future__ import print_function
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 # Copyright (c) 2007 Mike Higgins (Falstaff)
 # Modifications from the original:
 #    Copyright (C) 2007 Kovid Goyal <kovid@kovidgoyal.net>
@@ -108,11 +109,10 @@ def appendTextElements(e, contentsList, se):
     """ A helper function to convert text streams into the proper elements. """
 
     def uconcat(text, newText, se):
-        if type(newText) != type(text):
-            if type(text) is str:
-                text = text.decode(se)
-            else:
-                newText = newText.decode(se)
+        if isinstance(text, bytes):
+            text = text.decode(se)
+        if isinstance(newText, bytes):
+            newText = newText.decode(se)
 
         return text + newText
 
@@ -228,8 +228,8 @@ class LrsAttributes(object):
             if name not in self.attrs and name not in alsoAllow:
                 raise LrsError("%s does not support setting %s" %
                         (self.__class__.__name__, name))
-            if type(value) is int:
-                value = str(value)
+            if isinstance(value, int):
+                value = unicode_type(value)
             self.attrs[name] = value
 
 
@@ -333,13 +333,13 @@ class LrsObject(object):
     def lrsObjectElement(self, name, objlabel="objlabel", labelName=None,
             labelDecorate=True, **settings):
         element = Element(name)
-        element.attrib["objid"] = str(self.objId)
+        element.attrib["objid"] = unicode_type(self.objId)
         if labelName is None:
             labelName = name
         if labelDecorate:
             label = "%s.%d" % (labelName, self.objId)
         else:
-            label = str(self.objId)
+            label = unicode_type(self.objId)
         element.attrib[objlabel] = label
         element.attrib.update(settings)
         return element
@@ -565,7 +565,7 @@ class Book(Delegator):
         factor = base_font_size / old_base_font_size
 
         def rescale(old):
-            return str(int(int(old) * factor))
+            return unicode_type(int(int(old) * factor))
 
         text_blocks = list(main.get_all(lambda x: isinstance(x, TextBlock)))
         for tb in text_blocks:
@@ -696,7 +696,7 @@ class TableOfContents(object):
     def addTocEntry(self, tocLabel, textBlock):
         if not isinstance(textBlock, (Canvas, TextBlock, ImageBlock, RuledLine)):
             raise LrsError("TOC destination must be a Canvas, TextBlock, ImageBlock or RuledLine"+
-                            " not a " + str(type(textBlock)))
+                            " not a " + unicode_type(type(textBlock)))
 
         if textBlock.parent is None:
             raise LrsError("TOC text block must be already appended to a page")
@@ -746,8 +746,8 @@ class TocLabel(object):
 
     def toElement(self, se):
         return ElementWithText("TocLabel", self.label,
-                 refobj=str(self.textBlock.objId),
-                 refpage=str(self.textBlock.parent.objId))
+                 refobj=unicode_type(self.textBlock.objId),
+                 refpage=unicode_type(self.textBlock.parent.objId))
 
 
 class BookInfo(object):
@@ -808,7 +808,7 @@ class DocInfo(object):
         self.thumbnail = None
         self.language = "en"
         self.creator  = None
-        self.creationdate = str(isoformat(date.today()))
+        self.creationdate = unicode_type(isoformat(date.today()))
         self.producer = "%s v%s"%(__appname__, __version__)
         self.numberofpages = "0"
 
@@ -832,7 +832,7 @@ class DocInfo(object):
         docInfo.append(ElementWithText("Creator", self.creator))
         docInfo.append(ElementWithText("CreationDate", self.creationdate))
         docInfo.append(ElementWithText("Producer", self.producer))
-        docInfo.append(ElementWithText("SumPage", str(self.numberofpages)))
+        docInfo.append(ElementWithText("SumPage", unicode_type(self.numberofpages)))
         return docInfo
 
 
@@ -1094,7 +1094,7 @@ class LrsStyle(LrsObject, LrsAttributes, LrsContainer):
         self.elementName = elementName
         self.objectsAppended = False
         # self.label = "%s.%d" % (elementName, self.objId)
-        # self.label = str(self.objId)
+        # self.label = unicode_type(self.objId)
         # self.parent = None
 
     def update(self, settings):
@@ -1104,11 +1104,11 @@ class LrsStyle(LrsObject, LrsAttributes, LrsContainer):
             self.attrs[name] = value
 
     def getLabel(self):
-        return str(self.objId)
+        return unicode_type(self.objId)
 
     def toElement(self, se):
         element = Element(self.elementName, stylelabel=self.getLabel(),
-                objid=str(self.objId))
+                objid=unicode_type(self.objId))
         element.attrib.update(self.attrs)
         return element
 
@@ -1236,14 +1236,14 @@ class PageStyle(LrsStyle):
             del settings[evenbase]
             if evenObj.parent is None:
                 parent.append(evenObj)
-            settings[evenbase + "id"] = str(evenObj.objId)
+            settings[evenbase + "id"] = unicode_type(evenObj.objId)
 
         if oddbase in settings:
             oddObj = settings[oddbase]
             del settings[oddbase]
             if oddObj.parent is None:
                 parent.append(oddObj)
-            settings[oddbase + "id"] = str(oddObj.objId)
+            settings[oddbase + "id"] = unicode_type(oddObj.objId)
 
     def appendReferencedObjects(self, parent):
         if self.objectsAppended:
@@ -1580,7 +1580,7 @@ class DropCaps(LrsTextTag):
         return self.text is None or not self.text.strip()
 
     def toElement(self, se):
-        elem =  Element('DrawChar', line=str(self.line))
+        elem =  Element('DrawChar', line=unicode_type(self.line))
         appendTextElements(elem, self.contents, se)
         return elem
 
@@ -1656,7 +1656,7 @@ class JumpTo(LrsContainer):
         self.textBlock = textBlock
 
     def toElement(self, se):
-        return Element("JumpTo", refpage=str(self.textBlock.parent.objId), refobj=str(self.textBlock.objId))
+        return Element("JumpTo", refpage=unicode_type(self.textBlock.parent.objId), refobj=unicode_type(self.textBlock.objId))
 
 
 class Plot(LrsSimpleChar1, LrsContainer):
@@ -1688,8 +1688,8 @@ class Plot(LrsSimpleChar1, LrsContainer):
             parent.append(self.obj)
 
     def toElement(self, se):
-        elem =  Element('Plot', xsize=str(self.xsize), ysize=str(self.ysize),
-                                refobj=str(self.obj.objId))
+        elem =  Element('Plot', xsize=unicode_type(self.xsize), ysize=unicode_type(self.ysize),
+                                refobj=unicode_type(self.obj.objId))
         if self.adjustment:
             elem.set('adjustment', self.adjustment)
         return elem
@@ -1771,7 +1771,7 @@ class Space(LrsSimpleChar1, LrsContainer):
         if self.xsize == 0:
             return
 
-        return Element("Space", xsize=str(self.xsize))
+        return Element("Space", xsize=unicode_type(self.xsize))
 
     def toLrfContainer(self, lrfWriter, container):
         if self.xsize != 0:
@@ -1858,7 +1858,7 @@ class Span(LrsSimpleChar1, LrsContainer):
     def toElement(self, se):
         element = Element('Span')
         for (key, value) in self.attrs.items():
-            element.set(key, str(value))
+            element.set(key, unicode_type(value))
 
         appendTextElements(element, self.contents, se)
         return element
@@ -1871,9 +1871,9 @@ class EmpLine(LrsTextTag, LrsSimpleChar1):
     def __init__(self, text=None, emplineposition='before', emplinetype='solid'):
         LrsTextTag.__init__(self, text, [LrsSimpleChar1])
         if emplineposition not in self.__class__.emplinepositions:
-            raise LrsError('emplineposition for an EmpLine must be one of: '+str(self.__class__.emplinepositions))
+            raise LrsError('emplineposition for an EmpLine must be one of: '+unicode_type(self.__class__.emplinepositions))
         if emplinetype not in self.__class__.emplinetypes:
-            raise LrsError('emplinetype for an EmpLine must be one of: '+str(self.__class__.emplinetypes))
+            raise LrsError('emplinetype for an EmpLine must be one of: '+unicode_type(self.__class__.emplinetypes))
 
         self.emplinetype     = emplinetype
         self.emplineposition = emplineposition
@@ -1933,9 +1933,9 @@ class BlockSpace(LrsContainer):
         element = Element("BlockSpace")
 
         if self.xspace != 0:
-            element.attrib["xspace"] = str(self.xspace)
+            element.attrib["xspace"] = unicode_type(self.xspace)
         if self.yspace != 0:
-            element.attrib["yspace"] = str(self.yspace)
+            element.attrib["yspace"] = unicode_type(self.yspace)
 
         return element
 
@@ -1979,7 +1979,7 @@ class CharButton(LrsSimpleChar1, LrsContainer):
         container.appendLrfTag(LrfTag("CharButtonEnd"))
 
     def toElement(self, se):
-        cb = Element("CharButton", refobj=str(self.button.objId))
+        cb = Element("CharButton", refobj=unicode_type(self.button.objId))
         appendTextElements(cb, self.contents, se)
         return cb
 
@@ -2081,8 +2081,8 @@ class JumpButton(LrsObject, LrsContainer):
         b = self.lrsObjectElement("Button")
         pb = SubElement(b, "PushButton")
         SubElement(pb, "JumpTo",
-            refpage=str(self.textBlock.parent.objId),
-            refobj=str(self.textBlock.objId))
+            refpage=unicode_type(self.textBlock.parent.objId),
+            refobj=unicode_type(self.textBlock.objId))
         return b
 
 
@@ -2230,8 +2230,8 @@ class PutObj(LrsContainer):
             self.content.objId)))
 
     def toElement(self, se):
-        el = Element("PutObj", x1=str(self.x1), y1=str(self.y1),
-                    refobj=str(self.content.objId))
+        el = Element("PutObj", x1=unicode_type(self.x1), y1=unicode_type(self.y1),
+                    refobj=unicode_type(self.content.objId))
         return el
 
 
@@ -2314,9 +2314,9 @@ class Image(LrsObject, LrsContainer, LrsAttributes):
 
     def toElement(self, se):
         element = self.lrsObjectElement("Image", **self.attrs)
-        element.set("refstream", str(self.refstream.objId))
+        element.set("refstream", unicode_type(self.refstream.objId))
         for name in ["x0", "y0", "x1", "y1", "xsize", "ysize"]:
-            element.set(name, str(getattr(self, name)))
+            element.set(name, unicode_type(getattr(self, name)))
         return element
 
     def toLrf(self, lrfWriter):
@@ -2397,9 +2397,9 @@ class ImageBlock(LrsObject, LrsContainer, LrsAttributes):
 
     def toElement(self, se):
         element = self.lrsObjectElement("ImageBlock", **self.attrs)
-        element.set("refstream", str(self.refstream.objId))
+        element.set("refstream", unicode_type(self.refstream.objId))
         for name in ["x0", "y0", "x1", "y1", "xsize", "ysize"]:
-            element.set(name, str(getattr(self, name)))
+            element.set(name, unicode_type(getattr(self, name)))
         element.text = self.alttext
         return element
 
diff --git a/src/calibre/ebooks/lrf/tags.py b/src/calibre/ebooks/lrf/tags.py
index 62de1a3a78..5f36ca950d 100644
--- a/src/calibre/ebooks/lrf/tags.py
+++ b/src/calibre/ebooks/lrf/tags.py
@@ -1,3 +1,5 @@
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
 ''''''
@@ -5,7 +7,7 @@ __copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
 import struct
 
 from calibre.ebooks.lrf import LRFParseError
-from polyglot.builtins import unicode_type, string_or_bytes
+from polyglot.builtins import unicode_type
 
 
 class Tag(object):
@@ -196,7 +198,7 @@ class Tag(object):
         self.id = 0xF500 + tag_id[0]
 
         size, self.name = self.__class__.tags[tag_id[0]]
-        if isinstance(size, string_or_bytes):
+        if isinstance(size, unicode_type):
             parser = getattr(self, size + '_parser')
             self.contents = parser(stream)
         else:
diff --git a/src/calibre/ebooks/metadata/__init__.py b/src/calibre/ebooks/metadata/__init__.py
index 1dd23171d1..37b9502265 100644
--- a/src/calibre/ebooks/metadata/__init__.py
+++ b/src/calibre/ebooks/metadata/__init__.py
@@ -1,5 +1,7 @@
 #!/usr/bin/env python2
 # vim:fileencoding=utf-8
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2008, Kovid Goyal kovid@kovidgoyal.net'
 __docformat__ = 'restructuredtext en'
@@ -26,9 +28,9 @@ except:
 def string_to_authors(raw):
     if not raw:
         return []
-    raw = raw.replace('&&', u'\uffff')
+    raw = raw.replace('&&', '\uffff')
     raw = _author_pat.sub('&', raw)
-    authors = [a.strip().replace(u'\uffff', '&') for a in raw.split('&')]
+    authors = [a.strip().replace('\uffff', '&') for a in raw.split('&')]
     return [a for a in authors if a]
 
 
@@ -41,7 +43,7 @@ def authors_to_string(authors):
 
 def remove_bracketed_text(src, brackets=None):
     if brackets is None:
-        brackets = {u'(': u')', u'[': u']', u'{': u'}'}
+        brackets = {'(': ')', '[': ']', '{': '}'}
     from collections import Counter
     counts = Counter()
     buf = []
@@ -56,12 +58,12 @@ def remove_bracketed_text(src, brackets=None):
                 counts[idx] -= 1
         elif sum(itervalues(counts)) < 1:
             buf.append(char)
-    return u''.join(buf)
+    return ''.join(buf)
 
 
 def author_to_author_sort(author, method=None):
     if not author:
-        return u''
+        return ''
     sauthor = remove_bracketed_text(author).strip()
     tokens = sauthor.split()
     if len(tokens) < 2:
@@ -72,13 +74,13 @@ def author_to_author_sort(author, method=None):
     ltoks = frozenset(x.lower() for x in tokens)
     copy_words = frozenset(x.lower() for x in tweaks['author_name_copywords'])
     if ltoks.intersection(copy_words):
-        method = u'copy'
+        method = 'copy'
 
-    if method == u'copy':
+    if method == 'copy':
         return author
 
     prefixes = {force_unicode(y).lower() for y in tweaks['author_name_prefixes']}
-    prefixes |= {y+u'.' for y in prefixes}
+    prefixes |= {y+'.' for y in prefixes}
     while True:
         if not tokens:
             return author
@@ -89,9 +91,9 @@ def author_to_author_sort(author, method=None):
             break
 
     suffixes = {force_unicode(y).lower() for y in tweaks['author_name_suffixes']}
-    suffixes |= {y+u'.' for y in suffixes}
+    suffixes |= {y+'.' for y in suffixes}
 
-    suffix = u''
+    suffix = ''
     while True:
         if not tokens:
             return author
@@ -103,7 +105,7 @@ def author_to_author_sort(author, method=None):
             break
     suffix = suffix.strip()
 
-    if method == u'comma' and u',' in u''.join(tokens):
+    if method == 'comma' and ',' in ''.join(tokens):
         return author
 
     atokens = tokens[-1:] + tokens[:-1]
@@ -111,10 +113,10 @@ def author_to_author_sort(author, method=None):
     if suffix:
         atokens.append(suffix)
 
-    if method != u'nocomma' and num_toks > 1:
-        atokens[0] += u','
+    if method != 'nocomma' and num_toks > 1:
+        atokens[0] += ','
 
-    return u' '.join(atokens)
+    return ' '.join(atokens)
 
 
 def authors_to_sort_string(authors):
@@ -154,7 +156,7 @@ def get_title_sort_pat(lang=None):
     return ans
 
 
-_ignore_starts = u'\'"'+u''.join(codepoint_to_chr(x) for x in
+_ignore_starts = '\'"'+''.join(codepoint_to_chr(x) for x in
         list(range(0x2018, 0x201e))+[0x2032, 0x2033])
 
 
@@ -187,7 +189,7 @@ coding = list(zip(
 
 def roman(num):
     if num <= 0 or num >= 4000 or int(num) != num:
-        return str(num)
+        return unicode_type(num)
     result = []
     for d, r in coding:
         while num >= d:
@@ -202,7 +204,7 @@ def fmt_sidx(i, fmt='%.2f', use_roman=False):
     try:
         i = float(i)
     except TypeError:
-        return str(i)
+        return unicode_type(i)
     if int(i) == float(i):
         return roman(int(i)) if use_roman else '%d'%int(i)
     return fmt%i
@@ -312,7 +314,7 @@ class ResourceCollection(object):
         return '[%s]'%', '.join(resources)
 
     def __repr__(self):
-        return str(self)
+        return unicode_type(self)
 
     def append(self, resource):
         if not isinstance(resource, Resource):
@@ -374,7 +376,7 @@ def check_isbn13(isbn):
         check = 10 - (sum(products)%10)
         if check == 10:
             check = 0
-        if str(check) == isbn[12]:
+        if unicode_type(check) == isbn[12]:
             return isbn
     except Exception:
         pass
@@ -430,12 +432,9 @@ def check_doi(doi):
     return None
 
 
-def rating_to_stars(value, allow_half_stars=False, star=u'★', half=u'½'):
+def rating_to_stars(value, allow_half_stars=False, star='★', half='½'):
     r = max(0, min(int(value or 0), 10))
-    if allow_half_stars:
-        ans = star * (r // 2)
-        if r % 2:
+    ans = star * (r // 2)
+    if allow_half_stars and r % 2:
             ans += half
-    else:
-        ans = star * int(r/2.0)
     return ans
diff --git a/src/calibre/ebooks/metadata/archive.py b/src/calibre/ebooks/metadata/archive.py
index 5ff350858e..fb24ae205d 100644
--- a/src/calibre/ebooks/metadata/archive.py
+++ b/src/calibre/ebooks/metadata/archive.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
-from __future__ import with_statement
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
@@ -10,7 +10,7 @@ import os
 from contextlib import closing
 
 from calibre.customize import FileTypePlugin
-from polyglot.builtins import filter
+from polyglot.builtins import filter, unicode_type
 
 
 def is_comic(list_of_names):
@@ -142,7 +142,7 @@ def get_comic_book_info(d, mi, series_index='volume'):
         from datetime import date
         try:
             dt = date(puby, 6 if pubm is None else pubm, 15)
-            dt = parse_only_date(str(dt))
+            dt = parse_only_date(unicode_type(dt))
             mi.pubdate = dt
         except:
             pass
diff --git a/src/calibre/ebooks/metadata/book/__init__.py b/src/calibre/ebooks/metadata/book/__init__.py
index 1579a042d9..d1f3c4ff4d 100644
--- a/src/calibre/ebooks/metadata/book/__init__.py
+++ b/src/calibre/ebooks/metadata/book/__init__.py
@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
diff --git a/src/calibre/ebooks/metadata/book/base.py b/src/calibre/ebooks/metadata/book/base.py
index edd7ae9557..ff59edaff1 100644
--- a/src/calibre/ebooks/metadata/book/base.py
+++ b/src/calibre/ebooks/metadata/book/base.py
@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
@@ -24,7 +25,7 @@ SIMPLE_SET = frozenset(SIMPLE_GET - {'identifiers'})
 
 def human_readable(size, precision=2):
     """ Convert a size in bytes into megabytes """
-    return ('%.'+str(precision)+'f'+ 'MB') % ((size/(1024.*1024.)),)
+    return ('%.'+unicode_type(precision)+'f'+ 'MB') % (size/(1024*1024),)
 
 
 NULL_VALUES = {
@@ -607,13 +608,13 @@ class Metadata(object):
         return authors_to_string(self.authors)
 
     def format_tags(self):
-        return u', '.join([unicode_type(t) for t in sorted(self.tags, key=sort_key)])
+        return ', '.join([unicode_type(t) for t in sorted(self.tags, key=sort_key)])
 
-    def format_rating(self, v=None, divide_by=1.0):
+    def format_rating(self, v=None, divide_by=1):
         if v is None:
             if self.rating is not None:
                 return unicode_type(self.rating/divide_by)
-            return u'None'
+            return 'None'
         return unicode_type(v/divide_by)
 
     def format_field(self, key, series_with_index=True):
@@ -662,7 +663,7 @@ class Metadata(object):
             elif datatype == 'bool':
                 res = _('Yes') if res else _('No')
             elif datatype == 'rating':
-                res = u'%.2g'%(res/2.0)
+                res = '%.2g'%(res/2)
             elif datatype in ['int', 'float']:
                 try:
                     fmt = cmeta['display'].get('number_format', None)
@@ -702,7 +703,7 @@ class Metadata(object):
             elif datatype == 'datetime':
                 res = format_date(res, fmeta['display'].get('date_format','dd MMM yyyy'))
             elif datatype == 'rating':
-                res = u'%.2g'%(res/2.0)
+                res = '%.2g'%(res/2)
             elif key == 'size':
                 res = human_readable(res)
             return (name, unicode_type(res), orig_res, fmeta)
@@ -719,7 +720,7 @@ class Metadata(object):
         ans = []
 
         def fmt(x, y):
-            ans.append(u'%-20s: %s'%(unicode_type(x), unicode_type(y)))
+            ans.append('%-20s: %s'%(unicode_type(x), unicode_type(y)))
 
         fmt('Title', self.title)
         if self.title_sort:
@@ -733,14 +734,14 @@ class Metadata(object):
         if getattr(self, 'book_producer', False):
             fmt('Book Producer', self.book_producer)
         if self.tags:
-            fmt('Tags', u', '.join([unicode_type(t) for t in self.tags]))
+            fmt('Tags', ', '.join([unicode_type(t) for t in self.tags]))
         if self.series:
             fmt('Series', self.series + ' #%s'%self.format_series_index())
         if not self.is_null('languages'):
             fmt('Languages', ', '.join(self.languages))
         if self.rating is not None:
-            fmt('Rating', (u'%.2g'%(float(self.rating)/2.0)) if self.rating
-                    else u'')
+            fmt('Rating', ('%.2g'%(float(self.rating)/2)) if self.rating
+                    else '')
         if self.timestamp is not None:
             fmt('Timestamp', isoformat(self.timestamp))
         if self.pubdate is not None:
@@ -748,7 +749,7 @@ class Metadata(object):
         if self.rights is not None:
             fmt('Rights', unicode_type(self.rights))
         if self.identifiers:
-            fmt('Identifiers', u', '.join(['%s:%s'%(k, v) for k, v in
+            fmt('Identifiers', ', '.join(['%s:%s'%(k, v) for k, v in
                 iteritems(self.identifiers)]))
         if self.comments:
             fmt('Comments', self.comments)
@@ -758,7 +759,7 @@ class Metadata(object):
             if val:
                 (name, val) = self.format_field(key)
                 fmt(name, unicode_type(val))
-        return u'\n'.join(ans)
+        return '\n'.join(ans)
 
     def to_html(self):
         '''
@@ -772,10 +773,10 @@ class Metadata(object):
         ans += [(_('Producer'), unicode_type(self.book_producer))]
         ans += [(_('Comments'), unicode_type(self.comments))]
         ans += [('ISBN', unicode_type(self.isbn))]
-        ans += [(_('Tags'), u', '.join([unicode_type(t) for t in self.tags]))]
+        ans += [(_('Tags'), ', '.join([unicode_type(t) for t in self.tags]))]
         if self.series:
             ans += [(_('Series'), unicode_type(self.series) + ' #%s'%self.format_series_index())]
-        ans += [(_('Languages'), u', '.join(self.languages))]
+        ans += [(_('Languages'), ', '.join(self.languages))]
         if self.timestamp is not None:
             ans += [(_('Timestamp'), unicode_type(isoformat(self.timestamp, as_utc=False, sep=' ')))]
         if self.pubdate is not None:
@@ -788,8 +789,8 @@ class Metadata(object):
                 (name, val) = self.format_field(key)
                 ans += [(name, val)]
         for i, x in enumerate(ans):
-            ans[i] = u'<tr><td><b>%s</b></td><td>%s</td></tr>'%x
-        return u'<table>%s</table>'%u'\n'.join(ans)
+            ans[i] = '<tr><td><b>%s</b></td><td>%s</td></tr>'%x
+        return '<table>%s</table>'%'\n'.join(ans)
 
     if ispy3:
         __str__ = __unicode__representation__
diff --git a/src/calibre/ebooks/metadata/book/json_codec.py b/src/calibre/ebooks/metadata/book/json_codec.py
index 1275fd407f..7df3b8be98 100644
--- a/src/calibre/ebooks/metadata/book/json_codec.py
+++ b/src/calibre/ebooks/metadata/book/json_codec.py
@@ -1,9 +1,10 @@
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 '''
 Created on 4 Jun 2010
 
 @author: charles
 '''
-from __future__ import print_function
 
 import json, traceback
 from datetime import datetime, time
diff --git a/src/calibre/ebooks/metadata/cli.py b/src/calibre/ebooks/metadata/cli.py
index ebb2427eb5..28a8f7b0e4 100644
--- a/src/calibre/ebooks/metadata/cli.py
+++ b/src/calibre/ebooks/metadata/cli.py
@@ -1,4 +1,5 @@
-from __future__ import with_statement
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2009, Kovid Goyal kovid@kovidgoyal.net'
 __docformat__ = 'restructuredtext en'
diff --git a/src/calibre/ebooks/metadata/epub.py b/src/calibre/ebooks/metadata/epub.py
index 5e2ea5f503..153ce4cee9 100644
--- a/src/calibre/ebooks/metadata/epub.py
+++ b/src/calibre/ebooks/metadata/epub.py
@@ -1,5 +1,5 @@
 #!/usr/bin/env python2
-from __future__ import print_function, with_statement
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
diff --git a/src/calibre/ebooks/metadata/extz.py b/src/calibre/ebooks/metadata/extz.py
index 14d6588ce7..aab3a621ff 100644
--- a/src/calibre/ebooks/metadata/extz.py
+++ b/src/calibre/ebooks/metadata/extz.py
@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2011, John Schember <john@nachtimwald.com>'
diff --git a/src/calibre/ebooks/metadata/fb2.py b/src/calibre/ebooks/metadata/fb2.py
index bbd1aec7cc..93316484bc 100644
--- a/src/calibre/ebooks/metadata/fb2.py
+++ b/src/calibre/ebooks/metadata/fb2.py
@@ -1,5 +1,7 @@
 #!/usr/bin/env python2
 # vim:fileencoding=utf-8
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2011, Roman Mukhin <ramses_ru at hotmail.com>, '\
                 '2008, Anatoly Shipitsin <norguhtar at gmail.com>'
diff --git a/src/calibre/ebooks/metadata/kdl.py b/src/calibre/ebooks/metadata/kdl.py
index b95284193a..97249e0613 100644
--- a/src/calibre/ebooks/metadata/kdl.py
+++ b/src/calibre/ebooks/metadata/kdl.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
-from __future__ import print_function
 __license__   = 'GPL v3'
 __copyright__ = '2011, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
@@ -20,7 +20,7 @@ from polyglot.urllib import parse_qs, quote_plus
 URL = \
 "http://ww2.kdl.org/libcat/WhatsNext.asp?AuthorLastName={0}&AuthorFirstName=&SeriesName=&BookTitle={1}&CategoryID=0&cmdSearch=Search&Search=1&grouping="
 
-_ignore_starts = u'\'"'+u''.join(codepoint_to_chr(x) for x in list(range(0x2018, 0x201e))+[0x2032, 0x2033])
+_ignore_starts = '\'"'+''.join(codepoint_to_chr(x) for x in list(range(0x2018, 0x201e))+[0x2032, 0x2033])
 
 
 def get_series(title, authors, timeout=60):
diff --git a/src/calibre/ebooks/metadata/lit.py b/src/calibre/ebooks/metadata/lit.py
index fd63766f02..ae568ce0f7 100644
--- a/src/calibre/ebooks/metadata/lit.py
+++ b/src/calibre/ebooks/metadata/lit.py
@@ -1,3 +1,5 @@
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
 '''
diff --git a/src/calibre/ebooks/metadata/meta.py b/src/calibre/ebooks/metadata/meta.py
index caee318292..9d335c81c9 100644
--- a/src/calibre/ebooks/metadata/meta.py
+++ b/src/calibre/ebooks/metadata/meta.py
@@ -1,4 +1,5 @@
-from __future__ import with_statement
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
 
@@ -10,7 +11,7 @@ from calibre.ebooks.metadata.opf2 import OPF
 from calibre import isbytestring
 from calibre.customize.ui import get_file_type_metadata, set_file_type_metadata
 from calibre.ebooks.metadata import MetaInformation, string_to_authors
-from polyglot.builtins import getcwd
+from polyglot.builtins import getcwd, unicode_type
 
 _METADATA_PRIORITIES = [
                        'html', 'htm', 'xhtml', 'xhtm',
@@ -230,7 +231,7 @@ def forked_read_metadata(path, tdir):
         f.seek(0, 2)
         sz = f.tell()
         with lopen(os.path.join(tdir, 'size.txt'), 'wb') as s:
-            s.write(str(sz).encode('ascii'))
+            s.write(unicode_type(sz).encode('ascii'))
         f.seek(0)
         mi = get_metadata(f, fmt)
     if mi.cover_data and mi.cover_data[1]:
diff --git a/src/calibre/ebooks/metadata/mobi.py b/src/calibre/ebooks/metadata/mobi.py
index 7c80898901..79ddc84bac 100644
--- a/src/calibre/ebooks/metadata/mobi.py
+++ b/src/calibre/ebooks/metadata/mobi.py
@@ -2,8 +2,7 @@
 Retrieve and modify in-place Mobipocket book metadata.
 '''
 
-from __future__ import with_statement
-from __future__ import print_function
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2009, Kovid Goyal kovid@kovidgoyal.net and ' \
@@ -398,11 +397,11 @@ class MetadataUpdater(object):
                 self.original_exth_records.get(501, None) == 'EBOK' and
                 not added_501 and not share_not_sync):
             from uuid import uuid4
-            update_exth_record((113, str(uuid4())))
+            update_exth_record((113, unicode_type(uuid4())))
         # Add a 112 record with actual UUID
         if getattr(mi, 'uuid', None):
             update_exth_record((112,
-                    (u"calibre:%s" % mi.uuid).encode(self.codec, 'replace')))
+                    ("calibre:%s" % mi.uuid).encode(self.codec, 'replace')))
         if 503 in self.original_exth_records:
             update_exth_record((503, mi.title.encode(self.codec, 'replace')))
 
diff --git a/src/calibre/ebooks/metadata/odt.py b/src/calibre/ebooks/metadata/odt.py
index 5583d25bae..cb0d2e23e0 100644
--- a/src/calibre/ebooks/metadata/odt.py
+++ b/src/calibre/ebooks/metadata/odt.py
@@ -1,5 +1,4 @@
 #!/usr/bin/python2
-# -*- coding: utf-8 -*-
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:fdm=marker:ai
 #
 # Copyright (C) 2006 Søren Roug, European Environment Agency
@@ -19,7 +18,7 @@
 #
 # Contributor(s):
 #
-from __future__ import division
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 import zipfile, re, io
 import xml.sax.saxutils
@@ -37,22 +36,22 @@ from polyglot.builtins import string_or_bytes
 whitespace = re.compile(r'\s+')
 
 fields = {
-'title':            (DCNS,u'title'),
-'description':      (DCNS,u'description'),
-'subject':          (DCNS,u'subject'),
-'creator':          (DCNS,u'creator'),
-'date':             (DCNS,u'date'),
-'language':         (DCNS,u'language'),
-'generator':        (METANS,u'generator'),
-'initial-creator':  (METANS,u'initial-creator'),
-'keyword':          (METANS,u'keyword'),
-'editing-duration': (METANS,u'editing-duration'),
-'editing-cycles':   (METANS,u'editing-cycles'),
-'printed-by':       (METANS,u'printed-by'),
-'print-date':       (METANS,u'print-date'),
-'creation-date':    (METANS,u'creation-date'),
-'user-defined':     (METANS,u'user-defined'),
-# 'template':         (METANS,u'template'),
+    'title':            (DCNS, 'title'),
+    'description':      (DCNS, 'description'),
+    'subject':          (DCNS, 'subject'),
+    'creator':          (DCNS, 'creator'),
+    'date':             (DCNS, 'date'),
+    'language':         (DCNS, 'language'),
+    'generator':        (METANS, 'generator'),
+    'initial-creator':  (METANS, 'initial-creator'),
+    'keyword':          (METANS, 'keyword'),
+    'editing-duration': (METANS, 'editing-duration'),
+    'editing-cycles':   (METANS, 'editing-cycles'),
+    'printed-by':       (METANS, 'printed-by'),
+    'print-date':       (METANS, 'print-date'),
+    'creation-date':    (METANS, 'creation-date'),
+    'user-defined':     (METANS, 'user-defined'),
+    # 'template':         (METANS, 'template'),
 }
 
 
@@ -107,8 +106,8 @@ class odfmetaparser(xml.sax.saxutils.XMLGenerator):
 # location and not at the end
 #       if name == (METANS,u'template'):
 #           self._data = [attrs.get((XLINKNS,u'title'),'')]
-        if name == (METANS,u'user-defined'):
-            field = attrs.get((METANS,u'name'))
+        if name == (METANS, 'user-defined'):
+            field = attrs.get((METANS, 'name'))
         if field in self.deletefields:
             self.output.dowrite = False
         elif field in self.yieldfields:
@@ -120,15 +119,15 @@ class odfmetaparser(xml.sax.saxutils.XMLGenerator):
 
     def endElementNS(self, name, qname):
         field = name
-        if name == (METANS,u'user-defined'):
+        if name == (METANS, 'user-defined'):
             field = self._tag
-        if name == (OFFICENS,u'meta'):
+        if name == (OFFICENS, 'meta'):
             for k,v in self.addfields.items():
                 if len(v) > 0:
                     if isinstance(k, string_or_bytes):
-                        xml.sax.saxutils.XMLGenerator.startElementNS(self,(METANS,u'user-defined'),None,{(METANS,u'name'):k})
+                        xml.sax.saxutils.XMLGenerator.startElementNS(self,(METANS, 'user-defined'),None,{(METANS, 'name'):k})
                         xml.sax.saxutils.XMLGenerator.characters(self, v)
-                        xml.sax.saxutils.XMLGenerator.endElementNS(self, (METANS,u'user-defined'),None)
+                        xml.sax.saxutils.XMLGenerator.endElementNS(self, (METANS, 'user-defined'),None)
                     else:
                         xml.sax.saxutils.XMLGenerator.startElementNS(self, k, None, {})
                         xml.sax.saxutils.XMLGenerator.characters(self, v)
@@ -140,7 +139,7 @@ class odfmetaparser(xml.sax.saxutils.XMLGenerator):
         self.seenfields[texttag] = self.data()
         # OpenOffice has the habit to capitalize custom properties, so we add a
         # lowercase version for easy access
-        if texttag[:4].lower() == u'opf.':
+        if texttag[:4].lower() == 'opf.':
             self.seenfields[texttag.lower()] = self.data()
 
         if field in self.deletefields:
@@ -245,7 +244,7 @@ def read_cover(stream, zin, mi, opfmeta, extract_cover):
         except Exception:
             continue
         imgnum += 1
-        if opfmeta and frm.getAttribute('name').lower() == u'opf.cover':
+        if opfmeta and frm.getAttribute('name').lower() == 'opf.cover':
             cover_href = i_href
             cover_data = (fmt, raw)
             cover_frame = frm.getAttribute('name')  # could have upper case
diff --git a/src/calibre/ebooks/metadata/pdb.py b/src/calibre/ebooks/metadata/pdb.py
index 48d8510312..29a1b00018 100644
--- a/src/calibre/ebooks/metadata/pdb.py
+++ b/src/calibre/ebooks/metadata/pdb.py
@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 '''
 Read meta information from pdb files.
@@ -59,4 +60,3 @@ def set_metadata(stream, mi):
 
     stream.seek(0)
     stream.write('%s\x00' % re.sub('[^-A-Za-z0-9 ]+', '_', mi.title).ljust(31, '\x00')[:31].encode('ascii', 'replace'))
-
diff --git a/src/calibre/ebooks/metadata/pdf.py b/src/calibre/ebooks/metadata/pdf.py
index 269e093634..fd0604d204 100644
--- a/src/calibre/ebooks/metadata/pdf.py
+++ b/src/calibre/ebooks/metadata/pdf.py
@@ -1,4 +1,5 @@
-from __future__ import with_statement
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
 '''Read meta information from PDF files'''
@@ -47,9 +48,9 @@ def read_info(outputdir, get_cover):
         return None
 
     for line in info_raw.splitlines():
-        if u':' not in line:
+        if ':' not in line:
             continue
-        field, val = line.partition(u':')[::2]
+        field, val = line.partition(':')[::2]
         val = val.strip()
         if field and val:
             ans[field] = val.strip()
diff --git a/src/calibre/ebooks/metadata/rar.py b/src/calibre/ebooks/metadata/rar.py
index 1e7d0584c9..e21a1cf7fe 100644
--- a/src/calibre/ebooks/metadata/rar.py
+++ b/src/calibre/ebooks/metadata/rar.py
@@ -1,4 +1,6 @@
 #!/usr/bin/env  python2
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2009, Kovid Goyal kovid@kovidgoyal.net'
 __docformat__ = 'restructuredtext en'
@@ -34,5 +36,3 @@ def get_metadata(stream):
                 mi.timestamp = None
                 return mi
     raise ValueError('No ebook found in RAR archive')
-
-
diff --git a/src/calibre/ebooks/metadata/rb.py b/src/calibre/ebooks/metadata/rb.py
index 251faeb00f..5361a15517 100644
--- a/src/calibre/ebooks/metadata/rb.py
+++ b/src/calibre/ebooks/metadata/rb.py
@@ -1,4 +1,5 @@
-from __future__ import print_function
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2008, Ashish Kulkarni <kulkarni.ashish@gmail.com>'
 '''Read meta information from RB files'''
@@ -19,7 +20,7 @@ def get_metadata(stream):
     stream.seek(0)
     try:
         if not stream.read(14) == MAGIC:
-            print(u'Couldn\'t read RB header from file', file=sys.stderr)
+            print('Couldn\'t read RB header from file', file=sys.stderr)
             return mi
         stream.read(10)
 
@@ -34,7 +35,7 @@ def get_metadata(stream):
             if flag == 2:
                 break
         else:
-            print(u'Couldn\'t find INFO from RB file', file=sys.stderr)
+            print('Couldn\'t find INFO from RB file', file=sys.stderr)
             return mi
 
         stream.seek(offset)
@@ -48,7 +49,7 @@ def get_metadata(stream):
             elif key.strip() == 'AUTHOR':
                 mi.authors = string_to_authors(value)
     except Exception as err:
-        msg = u'Couldn\'t read metadata from rb: %s with error %s'%(mi.title, unicode_type(err))
+        msg = 'Couldn\'t read metadata from rb: %s with error %s'%(mi.title, unicode_type(err))
         prints(msg, file=sys.stderr)
         raise
     return mi
diff --git a/src/calibre/ebooks/metadata/snb.py b/src/calibre/ebooks/metadata/snb.py
index d488c0de0b..12bc843a0f 100644
--- a/src/calibre/ebooks/metadata/snb.py
+++ b/src/calibre/ebooks/metadata/snb.py
@@ -1,6 +1,6 @@
 '''Read meta information from SNB files'''
 
-from __future__ import with_statement
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Li Fanxi <lifanxi@freemindworld.com>'
diff --git a/src/calibre/ebooks/metadata/sources/__init__.py b/src/calibre/ebooks/metadata/sources/__init__.py
index 31be9f7fc6..0f9dc4e7f8 100644
--- a/src/calibre/ebooks/metadata/sources/__init__.py
+++ b/src/calibre/ebooks/metadata/sources/__init__.py
@@ -1,9 +1,7 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2011, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
-
-
-
diff --git a/src/calibre/ebooks/metadata/sources/amazon.py b/src/calibre/ebooks/metadata/sources/amazon.py
index 99e432e670..8555a85a8e 100644
--- a/src/calibre/ebooks/metadata/sources/amazon.py
+++ b/src/calibre/ebooks/metadata/sources/amazon.py
@@ -208,18 +208,18 @@ class Worker(Thread):  # Get details {{{
                 12: ['diciembre'],
             },
             'jp': {
-                1: [u'1月'],
-                2: [u'2月'],
-                3: [u'3月'],
-                4: [u'4月'],
-                5: [u'5月'],
-                6: [u'6月'],
-                7: [u'7月'],
-                8: [u'8月'],
-                9: [u'9月'],
-                10: [u'10月'],
-                11: [u'11月'],
-                12: [u'12月'],
+                1: ['1月'],
+                2: ['2月'],
+                3: ['3月'],
+                4: ['4月'],
+                5: ['5月'],
+                6: ['6月'],
+                7: ['7月'],
+                8: ['8月'],
+                9: ['9月'],
+                10: ['10月'],
+                11: ['11月'],
+                12: ['12月'],
             },
             'nl': {
                 1: ['januari'], 2: ['februari'], 3: ['maart'], 5: ['mei'], 6: ['juni'], 7: ['juli'], 8: ['augustus'], 10: ['oktober'],
@@ -294,10 +294,10 @@ class Worker(Thread):  # Get details {{{
             'ita': ('Italian', 'Italiano'),
             'deu': ('German', 'Deutsch'),
             'spa': ('Spanish', 'Espa\xf1ol', 'Espaniol'),
-            'jpn': ('Japanese', u'日本語'),
+            'jpn': ('Japanese', '日本語'),
             'por': ('Portuguese', 'Português'),
             'nld': ('Dutch', 'Nederlands',),
-            'chs': ('Chinese', u'中文', u'简体中文'),
+            'chs': ('Chinese', '中文', '简体中文'),
         }
         self.lang_map = {}
         for code, names in lm.items():
@@ -1134,9 +1134,9 @@ class Amazon(Source):
 
         # magic parameter to enable Japanese Shift_JIS encoding.
         if domain == 'jp':
-            q['__mk_ja_JP'] = u'カタカナ'
+            q['__mk_ja_JP'] = 'カタカナ'
         if domain == 'nl':
-            q['__mk_nl_NL'] = u'ÅMÅŽÕÑ'
+            q['__mk_nl_NL'] = 'ÅMÅŽÕÑ'
             if 'field-keywords' not in q:
                 q['field-keywords'] = ''
             for f in 'field-isbn field-title field-author'.split():
@@ -1604,18 +1604,18 @@ def manual_tests(domain, **kw):  # {{{
     all_tests['jp'] = [  # {{{
         (  # Adult filtering test
             {'identifiers': {'isbn': '4799500066'}},
-            [title_test(u'Ｂｉｔｃｈ Ｔｒａｐ'), ]
+            [title_test('Ｂｉｔｃｈ Ｔｒａｐ'), ]
         ),
 
         (  # isbn -> title, authors
             {'identifiers': {'isbn': '9784101302720'}},
-            [title_test(u'精霊の守り人',
-                        exact=True), authors_test([u'上橋 菜穂子'])
+            [title_test('精霊の守り人',
+                        exact=True), authors_test(['上橋 菜穂子'])
              ]
         ),
         (  # title, authors -> isbn (will use Shift_JIS encoding in query.)
-            {'title': u'考えない練習',
-             'authors': [u'小池 龍之介']},
+            {'title': '考えない練習',
+             'authors': ['小池 龍之介']},
             [isbn_test('9784093881067'), ]
         ),
     ]  # }}}
diff --git a/src/calibre/ebooks/metadata/sources/google.py b/src/calibre/ebooks/metadata/sources/google.py
index 08c40b3eb2..66f5787799 100644
--- a/src/calibre/ebooks/metadata/sources/google.py
+++ b/src/calibre/ebooks/metadata/sources/google.py
@@ -220,12 +220,10 @@ class GoogleBooks(Source):
             if author_tokens:
                 q += ('+' if q else '') + build_term('author', author_tokens)
 
-        if isinstance(q, type(u'')):
-            q = q.encode('utf-8')
         if not q:
             return None
         return BASE_URL + urlencode({
-            'q': q,
+            'q': q.encode('utf-8'),
             'max-results': 20,
             'start-index': 1,
             'min-viewability': 'none',
diff --git a/src/calibre/ebooks/metadata/toc.py b/src/calibre/ebooks/metadata/toc.py
index 52bfea8377..ec5ab025be 100644
--- a/src/calibre/ebooks/metadata/toc.py
+++ b/src/calibre/ebooks/metadata/toc.py
@@ -1,5 +1,6 @@
 #!/usr/bin/env  python2
-from __future__ import print_function
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid at kovidgoyal.net>'
 
@@ -69,7 +70,7 @@ class TOC(list):
     def __str__(self):
         lines = ['TOC: %s#%s %s'%(self.href, self.fragment, self.text)]
         for child in self:
-            c = str(child).splitlines()
+            c = unicode_type(child).splitlines()
             for l in c:
                 lines.append('\t'+l)
         return '\n'.join(lines)
@@ -245,8 +246,8 @@ class TOC(list):
     def render(self, stream, uid):
         root = E.ncx(
                 E.head(
-                    E.meta(name='dtb:uid', content=str(uid)),
-                    E.meta(name='dtb:depth', content=str(self.depth())),
+                    E.meta(name='dtb:uid', content=unicode_type(uid)),
+                    E.meta(name='dtb:depth', content=unicode_type(self.depth())),
                     E.meta(name='dtb:generator', content='%s (%s)'%(__appname__,
                         __version__)),
                     E.meta(name='dtb:totalPageCount', content='0'),
@@ -271,7 +272,7 @@ class TOC(list):
                     E.content(src=unicode_type(np.href)+(('#' + unicode_type(np.fragment))
                         if np.fragment else '')),
                     id=item_id,
-                    playOrder=str(np.play_order)
+                    playOrder=unicode_type(np.play_order)
             )
             au = getattr(np, 'author', None)
             if au:
diff --git a/src/calibre/ebooks/metadata/txt.py b/src/calibre/ebooks/metadata/txt.py
index b1a948f9bc..1a5c30bcb4 100644
--- a/src/calibre/ebooks/metadata/txt.py
+++ b/src/calibre/ebooks/metadata/txt.py
@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2009, John Schember <john@nachtimwald.com>'
diff --git a/src/calibre/ebooks/metadata/xisbn.py b/src/calibre/ebooks/metadata/xisbn.py
index f0ecb7dd69..075d8d52d6 100644
--- a/src/calibre/ebooks/metadata/xisbn.py
+++ b/src/calibre/ebooks/metadata/xisbn.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
-from __future__ import print_function
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
diff --git a/src/calibre/ebooks/metadata/zip.py b/src/calibre/ebooks/metadata/zip.py
index b3ba1723dc..c3d85089e4 100644
--- a/src/calibre/ebooks/metadata/zip.py
+++ b/src/calibre/ebooks/metadata/zip.py
@@ -1,4 +1,5 @@
-from __future__ import with_statement
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'