use contextmanagers for open()

src/calibre/ebooks/conversion/plugins/comic_input.py

@@ -102,7 +102,8 @@ class ComicInput(InputFormatPlugin):
                     '%s is not a valid comic collection'
                     ' no comics.txt was found in the file')
                         %stream.name)
-            raw = open('comics.txt', 'rb').read()
+            with open('comics.txt', 'rb') as f:
+                raw = f.read()
             if raw.startswith(codecs.BOM_UTF16_BE):
                 raw = raw.decode('utf-16-be')[1:]
             elif raw.startswith(codecs.BOM_UTF16_LE):
@@ -230,7 +231,7 @@ class ComicInput(InputFormatPlugin):
                                 _('Page')+' %d'%(i+1), play_order=po)
                         po += 1
         opf.set_toc(toc)
-        m, n = open(u'metadata.opf', 'wb'), open('toc.ncx', 'wb')
+        with open(u'metadata.opf', 'wb') as m, open('toc.ncx', 'wb') as n:
             opf.render(m, n, u'toc.ncx')
         return os.path.abspath(u'metadata.opf')
 

src/calibre/ebooks/conversion/plugins/epub_output.py

@@ -367,7 +367,8 @@ class EPUBOutput(OutputFormatPlugin):
                 if tag.tail:
                     tag.tail = tag.tail.strip()
             compressed = etree.tostring(tree.getroot(), encoding='utf-8')
-            open(ncx_path, 'wb').write(compressed)
+            with open(ncx_path, 'wb') as f:
+                f.write(compressed)
     # }}}
 
     def workaround_ade_quirks(self):  # {{{

src/calibre/ebooks/conversion/plugins/html_output.py

@@ -91,17 +91,20 @@ class HTMLOutput(OutputFormatPlugin):
 
         # read template files
         if opts.template_html_index is not None:
-            template_html_index_data = open(opts.template_html_index, 'rb').read()
+            with open(opts.template_html_index, 'rb') as f:
+                template_html_index_data = f.read()
         else:
             template_html_index_data = P('templates/html_export_default_index.tmpl', data=True)
 
         if opts.template_html is not None:
-            template_html_data = open(opts.template_html, 'rb').read()
+            with open(opts.template_html, 'rb') as f:
+                template_html_data = f.read()
         else:
             template_html_data = P('templates/html_export_default.tmpl', data=True)
 
         if opts.template_css is not None:
-            template_css_data = open(opts.template_css, 'rb').read()
+            with open(opts.template_css, 'rb') as f:
+                template_css_data = f.read()
         else:
             template_css_data = P('templates/html_export_default.css', data=True)
 

src/calibre/ebooks/conversion/plugins/snb_input.py

@@ -96,15 +96,14 @@ class SNBInput(InputFormatPlugin):
                     if data is None:
                         continue
                     snbc = etree.fromstring(data)
-                    outputFile = open(os.path.join(tdir, fname), 'wb')
                     lines = []
                     for line in snbc.find('.//body'):
                         if line.tag == 'text':
                             lines.append(u'<p>%s</p>' % html_encode(line.text))
                         elif line.tag == 'img':
                             lines.append(u'<p><img src="%s" /></p>' % html_encode(line.text))
-                    outputFile.write((HTML_TEMPLATE % (chapterName, u'\n'.join(lines))).encode('utf-8', 'replace'))
+                    with open(os.path.join(tdir, fname), 'wb') as f:
-                    outputFile.close()
+                        f.write((HTML_TEMPLATE % (chapterName, u'\n'.join(lines))).encode('utf-8', 'replace'))
                     oeb.toc.add(ch.text, fname)
                     id, href = oeb.manifest.generate(id='html',
                         href=ascii_filename(fname))

src/calibre/ebooks/conversion/plugins/snb_output.py

@@ -113,9 +113,8 @@ class SNBOutput(OutputFormatPlugin):
                 etree.SubElement(headTree, "cover").text = ProcessFileName(href)
             else:
                 etree.SubElement(headTree, "cover")
-            bookInfoFile = open(os.path.join(snbfDir, 'book.snbf'), 'wb')
+            with open(os.path.join(snbfDir, 'book.snbf'), 'wb') as f:
-            bookInfoFile.write(etree.tostring(bookInfoTree, pretty_print=True, encoding='utf-8'))
+                f.write(etree.tostring(bookInfoTree, pretty_print=True, encoding='utf-8'))
-            bookInfoFile.close()
 
             # Output TOC
             tocInfoTree = etree.Element("toc-snbf")
@@ -168,9 +167,8 @@ class SNBOutput(OutputFormatPlugin):
 
             etree.SubElement(tocHead, "chapters").text = '%d' % len(tocBody)
 
-            tocInfoFile = open(os.path.join(snbfDir, 'toc.snbf'), 'wb')
+            with open(os.path.join(snbfDir, 'toc.snbf'), 'wb') as f:
-            tocInfoFile.write(etree.tostring(tocInfoTree, pretty_print=True, encoding='utf-8'))
+                f.write(etree.tostring(tocInfoTree, pretty_print=True, encoding='utf-8'))
-            tocInfoFile.close()
 
             # Output Files
             oldTree = None
@@ -185,9 +183,8 @@ class SNBOutput(OutputFormatPlugin):
                     else:
                         if oldTree is not None and mergeLast:
                             log.debug('Output the modified chapter again: %s' % lastName)
-                            outputFile = open(os.path.join(snbcDir, lastName), 'wb')
+                            with open(os.path.join(snbcDir, lastName), 'wb') as f:
-                            outputFile.write(etree.tostring(oldTree, pretty_print=True, encoding='utf-8'))
+                                f.write(etree.tostring(oldTree, pretty_print=True, encoding='utf-8'))
-                            outputFile.close()
                             mergeLast = False
 
                     log.debug('Converting %s to snbc...' % item.href)
@@ -201,9 +198,8 @@ class SNBOutput(OutputFormatPlugin):
                                 postfix = '_' + subName
                             lastName = ProcessFileName(item.href + postfix + ".snbc")
                             oldTree = snbcTrees[subName]
-                            outputFile = open(os.path.join(snbcDir, lastName), 'wb')
+                            with open(os.path.join(snbcDir, lastName), 'wb') as f:
-                            outputFile.write(etree.tostring(oldTree, pretty_print=True, encoding='utf-8'))
+                                f.write(etree.tostring(oldTree, pretty_print=True, encoding='utf-8'))
-                            outputFile.close()
                     else:
                         log.debug('Merge %s with last TOC item...' % item.href)
                         snbwriter.merge_content(oldTree, oeb_book, item, [('', _("Start"))], opts)
@@ -211,9 +207,8 @@ class SNBOutput(OutputFormatPlugin):
             # Output the last one if needed
             log.debug('Output the last modified chapter again: %s' % lastName)
             if oldTree is not None and mergeLast:
-                outputFile = open(os.path.join(snbcDir, lastName), 'wb')
+                with open(os.path.join(snbcDir, lastName), 'wb') as f:
-                outputFile.write(etree.tostring(oldTree, pretty_print=True, encoding='utf-8'))
+                    f.write(etree.tostring(oldTree, pretty_print=True, encoding='utf-8'))
-                outputFile.close()
                 mergeLast = False
 
             for item in m:

src/calibre/ebooks/lrf/lrfparser.py

@@ -79,7 +79,8 @@ class LRFDocument(LRFMetaFile):
 
     def write_files(self):
         for obj in chain(itervalues(self.image_map), itervalues(self.font_map)):
-            open(obj.file, 'wb').write(obj.stream)
+            with open(obj.file, 'wb') as f:
+                f.write(obj.stream)
 
     def to_xml(self, write_files=True):
         bookinfo = u'<BookInformation>\n<Info version="1.1">\n<BookInfo>\n'
@@ -96,7 +97,8 @@ class LRFDocument(LRFMetaFile):
             prefix = ascii_filename(self.metadata.title)
             bookinfo += u'<CThumbnail file="%s" />\n'%(prefix+'_thumbnail.'+self.doc_info.thumbnail_extension,)
             if write_files:
-                open(prefix+'_thumbnail.'+self.doc_info.thumbnail_extension, 'wb').write(th)
+                with open(prefix+'_thumbnail.'+self.doc_info.thumbnail_extension, 'wb') as f:
+                    f.write(th)
         bookinfo += u'<Language reading="">%s</Language>\n'%(self.doc_info.language,)
         bookinfo += u'<Creator reading="">%s</Creator>\n'%(self.doc_info.creator,)
         bookinfo += u'<Producer reading="">%s</Producer>\n'%(self.doc_info.producer,)
@@ -159,13 +161,13 @@ def main(args=sys.argv, logger=None):
         return 1
     if opts.out is None:
         opts.out = os.path.join(os.path.dirname(args[1]), os.path.splitext(os.path.basename(args[1]))[0]+".lrs")
-    o = codecs.open(os.path.abspath(os.path.expanduser(opts.out)), 'wb', 'utf-8')
-    o.write(u'<?xml version="1.0" encoding="UTF-8"?>\n')
     logger.info(_('Parsing LRF...'))
     d = LRFDocument(open(args[1], 'rb'))
     d.parse()
     logger.info(_('Creating XML...'))
-    o.write(d.to_xml(write_files=opts.output_resources))
+    with codecs.open(os.path.abspath(os.path.expanduser(opts.out)), 'wb', 'utf-8') as f:
+        f.write('<?xml version="1.0" encoding="UTF-8"?>\n')
+        f.write(d.to_xml(write_files=opts.output_resources))
     logger.info(_('LRS written to ')+opts.out)
     return 0
 

src/calibre/ebooks/lrf/meta.py

@@ -703,9 +703,8 @@ def main(args=sys.argv):
         lrf.producer = options.producer
     if options.thumbnail:
         path = os.path.expanduser(os.path.expandvars(options.thumbnail))
-        f = open(path, "rb")
+        with open(path, "rb") as f:
             lrf.thumbnail = f.read()
-        f.close()
     if options.book_id is not None:
         lrf.book_id = options.book_id
     if options.comment:
@@ -716,9 +715,8 @@ def main(args=sys.argv):
         td = "None"
         if t and len(t) > 0:
             td = os.path.basename(args[1])+"_thumbnail."+lrf.thumbail_extension()
-            f = open(td, "w")
+            with open(td, "w") as f:
                 f.write(t)
-            f.close()
 
     fields = LRFMetaFile.__dict__.items()
     fields.sort()
@@ -734,7 +732,8 @@ def main(args=sys.argv):
             ext, data = None, None
         if data:
             cover = os.path.splitext(os.path.basename(args[1]))[0]+"_cover."+ext
-            open(cover, 'wb').write(data)
+            with open(cover, 'wb') as f:
+                f.write(data)
             print('Cover:', cover)
         else:
             print('Could not find cover in the LRF file')