diff --git a/src/calibre/devices/errors.py b/src/calibre/devices/errors.py
index 4e35786b59..7449bbcb71 100644
--- a/src/calibre/devices/errors.py
+++ b/src/calibre/devices/errors.py
@@ -7,7 +7,6 @@ G{classtree ProtocolError}
 """
 
 
-
 class ProtocolError(Exception):
     """ The base class for all exceptions in this package """
 
diff --git a/src/calibre/ebooks/BeautifulSoup.py b/src/calibre/ebooks/BeautifulSoup.py
index e297330f4d..dad2ec5c3b 100644
--- a/src/calibre/ebooks/BeautifulSoup.py
+++ b/src/calibre/ebooks/BeautifulSoup.py
@@ -10,7 +10,6 @@ from bs4 import (  # noqa
 )
 
 
-
 def parse_html(markup):
     from calibre.ebooks.chardet import strip_encoding_declarations, xml_to_unicode, substitute_entites
     from calibre.utils.cleantext import clean_xml_chars
diff --git a/src/calibre/ebooks/djvu/djvubzzdec.py b/src/calibre/ebooks/djvu/djvubzzdec.py
index 84b8bd1a2f..fa19326a6b 100644
--- a/src/calibre/ebooks/djvu/djvubzzdec.py
+++ b/src/calibre/ebooks/djvu/djvubzzdec.py
@@ -1,8 +1,6 @@
 #!/usr/bin/env python
 # coding: utf-8
 
-
-
 __license__   = 'GPL v3'
 __copyright__ = '2011, Anthon van der Neut <A.van.der.Neut@ruamel.eu>'
 
diff --git a/src/calibre/ebooks/pml/__init__.py b/src/calibre/ebooks/pml/__init__.py
index 92cef986da..3670569966 100644
--- a/src/calibre/ebooks/pml/__init__.py
+++ b/src/calibre/ebooks/pml/__init__.py
@@ -6,7 +6,6 @@ __copyright__ = '2009, John Schember <john@nachtimwald.com>'
 __docformat__ = 'restructuredtext en'
 
 
-
 def r(*a):
     return list(range(*a))
 
diff --git a/src/calibre/ebooks/rtf2xml/__init__.py b/src/calibre/ebooks/rtf2xml/__init__.py
index 4decfc328b..2b4c891ecf 100644
--- a/src/calibre/ebooks/rtf2xml/__init__.py
+++ b/src/calibre/ebooks/rtf2xml/__init__.py
@@ -1,6 +1,3 @@
-import io
-
-
 def open_for_read(path):
     return open(path, encoding='utf-8', errors='replace')
 
diff --git a/src/calibre/ebooks/rtf2xml/check_encoding.py b/src/calibre/ebooks/rtf2xml/check_encoding.py
index 053d058100..f06a3dddb3 100644
--- a/src/calibre/ebooks/rtf2xml/check_encoding.py
+++ b/src/calibre/ebooks/rtf2xml/check_encoding.py
@@ -4,7 +4,6 @@
 import sys
 
 
-
 class CheckEncoding:
 
     def __init__(self, bug_handler):
diff --git a/src/calibre/ebooks/unihandecode/pykakasi/jisyo.py b/src/calibre/ebooks/unihandecode/pykakasi/jisyo.py
index 5b66e81a21..6d56bcf1d3 100644
--- a/src/calibre/ebooks/unihandecode/pykakasi/jisyo.py
+++ b/src/calibre/ebooks/unihandecode/pykakasi/jisyo.py
@@ -7,7 +7,6 @@
 from zlib import decompress
 
 
-
 class jisyo :
     kanwadict = None
     itaijidict = None
diff --git a/src/calibre/gui2/tweak_book/completion/utils.py b/src/calibre/gui2/tweak_book/completion/utils.py
index d071fb8fb4..d338a98a2f 100644
--- a/src/calibre/gui2/tweak_book/completion/utils.py
+++ b/src/calibre/gui2/tweak_book/completion/utils.py
@@ -1,8 +1,6 @@
 #!/usr/bin/env python
 # vim:fileencoding=utf-8
 
-
-
 __license__ = 'GPL v3'
 __copyright__ = '2014, Kovid Goyal <kovid at kovidgoyal.net>'