diff --git a/manual/custom.py b/manual/custom.py
index 2c9b31d514..b35ff29234 100644
--- a/manual/custom.py
+++ b/manual/custom.py
@@ -179,7 +179,7 @@ def generate_ebook_convert_help(preamble, app):
     raw += '\n\n.. contents::\n  :local:'
 
     raw += '\n\n' + options
-    for pl in sorted(input_format_plugins(), key=lambda x:x.name):
+    for pl in sorted(input_format_plugins(), key=lambda x: x.name):
         parser, plumber = create_option_parser(['ebook-convert',
             'dummyi.'+sorted(pl.file_types)[0], 'dummyo.epub', '-h'], default_log)
         groups = [(pl.name+ ' Options', '', g.option_list) for g in
@@ -279,7 +279,7 @@ def cli_docs(app):
     info(bold('creating CLI documentation...'))
     documented_cmds, undocumented_cmds = get_cli_docs()
 
-    documented_cmds.sort(cmp=lambda x, y: cmp(x[0], y[0]))
+    documented_cmds.sort(key=lambda x: x[0])
     undocumented_cmds.sort()
 
     documented = [' '*4 + c[0] for c in documented_cmds]
diff --git a/src/calibre/customize/profiles.py b/src/calibre/customize/profiles.py
index 2c7fead69f..1038d448be 100644
--- a/src/calibre/customize/profiles.py
+++ b/src/calibre/customize/profiles.py
@@ -233,7 +233,7 @@ input_profiles = [InputProfile, SonyReaderInput, SonyReader300Input,
         HanlinV5Input, CybookG3Input, CybookOpusInput, KindleInput, IlliadInput,
         IRexDR1000Input, IRexDR800Input, NookInput]
 
-input_profiles.sort(cmp=lambda x,y:cmp(x.name.lower(), y.name.lower()))
+input_profiles.sort(key=lambda x: x.name.lower())
 
 # }}}
 
@@ -870,4 +870,4 @@ output_profiles = [
     KindlePaperWhite3Output, KindleOasisOutput
 ]
 
-output_profiles.sort(cmp=lambda x,y:cmp(x.name.lower(), y.name.lower()))
+output_profiles.sort(key=lambda x: x.name.lower())
diff --git a/src/calibre/customize/ui.py b/src/calibre/customize/ui.py
index 1229cbf712..8bb9b5814f 100644
--- a/src/calibre/customize/ui.py
+++ b/src/calibre/customize/ui.py
@@ -727,9 +727,9 @@ def initialize_plugins(perf=False):
     # ipython
     sys.stdout, sys.stderr = ostdout, ostderr
     if perf:
-        for x in sorted(times, key=lambda x:times[x]):
+        for x in sorted(times, key=lambda x: times[x]):
             print('%50s: %.3f'%(x, times[x]))
-    _initialized_plugins.sort(cmp=lambda x,y:cmp(x.priority, y.priority), reverse=True)
+    _initialized_plugins.sort(key=lambda x: x.priority, reverse=True)
     reread_filetype_plugins()
     reread_metadata_plugins()
 
diff --git a/src/calibre/db/cli/cmd_list_categories.py b/src/calibre/db/cli/cmd_list_categories.py
index 0280455f66..6165c50877 100644
--- a/src/calibre/db/cli/cmd_list_categories.py
+++ b/src/calibre/db/cli/cmd_list_categories.py
@@ -149,9 +149,7 @@ def main(opts, args, dbctx):
         (not report_on or k in report_on)
     ]
 
-    categories.sort(
-        cmp=lambda x, y: cmp(x if x[0] != '#' else x[1:], y if y[0] != '#' else y[1:])
-    )
+    categories.sort(key=lambda x: x if x[0] != '#' else x[1:])
 
     def fmtr(v):
         v = v or 0
diff --git a/src/calibre/devices/__init__.py b/src/calibre/devices/__init__.py
index d3ee2b0f19..5ab3b38dee 100644
--- a/src/calibre/devices/__init__.py
+++ b/src/calibre/devices/__init__.py
@@ -82,8 +82,7 @@ def debug(ioreg_to_tmp=False, buf=None, plugins=None,
     out = partial(prints, file=buf)
 
     devplugins = device_plugins() if plugins is None else plugins
-    devplugins = list(sorted(devplugins, cmp=lambda
-            x,y:cmp(x.__class__.__name__, y.__class__.__name__)))
+    devplugins = list(sorted(devplugins, key=lambda x: x.__class__.__name__))
     if plugins is None:
         for d in devplugins:
             try:
diff --git a/src/calibre/devices/prs505/sony_cache.py b/src/calibre/devices/prs505/sony_cache.py
index c8db25b73a..0e5a90aaee 100644
--- a/src/calibre/devices/prs505/sony_cache.py
+++ b/src/calibre/devices/prs505/sony_cache.py
@@ -321,7 +321,7 @@ class XMLCache(object):
             # Only rebase ids of nodes that are immediate children of the
             # record root (that way playlist/itemnodes are unaffected
             items = root.xpath('child::*[@id]')
-            items.sort(cmp=lambda x,y:cmp(int(x.get('id')), int(y.get('id'))))
+            items.sort(key=lambda x: int(x.get('id')))
             idmap = {}
             for i, item in enumerate(items):
                 old = int(item.get('id'))
diff --git a/src/calibre/devices/usbms/device.py b/src/calibre/devices/usbms/device.py
index a7eb0b3567..b025ca7abf 100644
--- a/src/calibre/devices/usbms/device.py
+++ b/src/calibre/devices/usbms/device.py
@@ -537,7 +537,7 @@ class Device(DeviceConfig, DevicePlugin):
             if sz > 0:
                 nodes.append((x.split('/')[-1], sz))
 
-        nodes.sort(cmp=lambda x, y: cmp(x[1], y[1]))
+        nodes.sort(key=lambda x: x[1])
         if not nodes:
             return node
         return nodes[-1][0]
diff --git a/src/calibre/devices/winusb.py b/src/calibre/devices/winusb.py
index 0a7647cce0..dd927e5df4 100644
--- a/src/calibre/devices/winusb.py
+++ b/src/calibre/devices/winusb.py
@@ -995,8 +995,7 @@ def develop():  # {{{
     drive_letters = set()
     pprint(usb_devices)
     print()
-    devplugins = list(sorted(device_plugins(), cmp=lambda
-            x,y:cmp(x.__class__.__name__, y.__class__.__name__)))
+    devplugins = list(sorted(device_plugins(), key=lambda x: x.__class__.__name__))
     for dev in devplugins:
         dev.startup()
     for dev in devplugins:
diff --git a/src/calibre/ebooks/conversion/plumber.py b/src/calibre/ebooks/conversion/plumber.py
index 25ad577c8b..5d8e46fd67 100644
--- a/src/calibre/ebooks/conversion/plumber.py
+++ b/src/calibre/ebooks/conversion/plumber.py
@@ -821,7 +821,7 @@ OptionRecommendation(name='search_replace',
         if not html_files:
             raise ValueError(_('Could not find an e-book inside the archive'))
         html_files = [(f, os.stat(f).st_size) for f in html_files]
-        html_files.sort(cmp=lambda x, y: cmp(x[1], y[1]))
+        html_files.sort(key=lambda x: x[1])
         html_files = [f[0] for f in html_files]
         for q in ('toc', 'index'):
             for f in html_files:
diff --git a/src/calibre/ebooks/lit/writer.py b/src/calibre/ebooks/lit/writer.py
index fd292f4a03..490c06b42f 100644
--- a/src/calibre/ebooks/lit/writer.py
+++ b/src/calibre/ebooks/lit/writer.py
@@ -670,8 +670,7 @@ class LitWriter(object):
     def _build_dchunks(self):
         ddata = []
         directory = list(self._directory)
-        directory.sort(cmp=lambda x, y:
-            cmp(x.name.lower(), y.name.lower()))
+        directory.sort(key=lambda x: x.name.lower())
         qrn = 1 + (1 << 2)
         dchunk = io.BytesIO()
         dcount = 0
diff --git a/src/calibre/ebooks/metadata/lit.py b/src/calibre/ebooks/metadata/lit.py
index 330bf8cc86..d2f078487d 100644
--- a/src/calibre/ebooks/metadata/lit.py
+++ b/src/calibre/ebooks/metadata/lit.py
@@ -32,7 +32,7 @@ def get_metadata(stream):
                 except:
                     pass
                 break
-    covers.sort(cmp=lambda x, y:cmp(len(x[0]), len(y[0])), reverse=True)
+    covers.sort(key=lambda x: len(x[0]), reverse=True)
     idx = 0
     if len(covers) > 1:
         if covers[1][1] == covers[0][1]+'-standard':
diff --git a/src/calibre/ebooks/metadata/meta.py b/src/calibre/ebooks/metadata/meta.py
index de773ec8c6..7a8299dc19 100644
--- a/src/calibre/ebooks/metadata/meta.py
+++ b/src/calibre/ebooks/metadata/meta.py
@@ -41,8 +41,7 @@ def metadata_from_formats(formats, force_read_metadata=False, pattern=None):
 
 def _metadata_from_formats(formats, force_read_metadata=False, pattern=None):
     mi = MetaInformation(None, None)
-    formats.sort(cmp=lambda x,y: cmp(METADATA_PRIORITIES[path_to_ext(x)],
-                                     METADATA_PRIORITIES[path_to_ext(y)]))
+    formats.sort(key=lambda x: METADATA_PRIORITIES[path_to_ext(x)])
     extensions = list(map(path_to_ext, formats))
     if 'opf' in extensions:
         opf = formats[extensions.index('opf')]
@@ -241,4 +240,3 @@ def forked_read_metadata(path, tdir):
     opf = metadata_to_opf(mi, default_lang='und')
     with lopen(os.path.join(tdir, 'metadata.opf'), 'wb') as f:
         f.write(opf)
-
diff --git a/src/calibre/ebooks/oeb/transforms/guide.py b/src/calibre/ebooks/oeb/transforms/guide.py
index 29c5f2a93a..104a2fc1d5 100644
--- a/src/calibre/ebooks/oeb/transforms/guide.py
+++ b/src/calibre/ebooks/oeb/transforms/guide.py
@@ -28,7 +28,7 @@ class Clean(object):
                     else:
                         covers.append([self.oeb.guide[x], len(item.data)])
 
-            covers.sort(cmp=lambda x,y:cmp(x[1], y[1]), reverse=True)
+            covers.sort(key=lambda x: x[1], reverse=True)
             if covers:
                 ref = covers[0][0]
                 if len(covers) > 1:
@@ -53,4 +53,3 @@ class Clean(object):
                 if item.title and item.title.lower() == 'start':
                     continue
                 self.oeb.guide.remove(x)
-
diff --git a/src/calibre/ebooks/pdf/reflow.py b/src/calibre/ebooks/pdf/reflow.py
index a7708ea8ce..337147d8a7 100644
--- a/src/calibre/ebooks/pdf/reflow.py
+++ b/src/calibre/ebooks/pdf/reflow.py
@@ -169,7 +169,7 @@ class Column(object):
         self._post_add()
 
     def _post_add(self):
-        self.elements.sort(cmp=lambda x,y:cmp(x.bottom,y.bottom))
+        self.elements.sort(key=lambda x: x.bottom)
         self.top = self.elements[0].top
         self.bottom = self.elements[-1].bottom
         self.left, self.right = sys.maxint, 0
@@ -260,7 +260,7 @@ class Region(object):
 
     def add(self, columns):
         if not self.columns:
-            for x in sorted(columns, cmp=lambda x,y: cmp(x.left, y.left)):
+            for x in sorted(columns, key=lambda x: x.left):
                 self.columns.append(x)
         else:
             for i in range(len(columns)):
@@ -458,7 +458,7 @@ class Page(object):
         self.elements = list(self.texts)
         for img in page.xpath('descendant::img'):
             self.elements.append(Image(img, self.opts, self.log, idc))
-        self.elements.sort(cmp=lambda x,y:cmp(x.top, y.top))
+        self.elements.sort(key=lambda x: x.top)
 
     def coalesce_fragments(self):
 
@@ -580,7 +580,7 @@ class Page(object):
 
     def sort_into_columns(self, elem, neighbors):
         neighbors.add(elem)
-        neighbors = sorted(neighbors, cmp=lambda x,y:cmp(x.left, y.left))
+        neighbors = sorted(neighbors, key=lambda x: x.left)
         if self.opts.verbose > 3:
             self.log.debug('Neighbors:', [x.to_html() for x in neighbors])
         columns = [Column()]
@@ -595,7 +595,7 @@ class Page(object):
             if not added:
                 columns.append(Column())
                 columns[-1].add(x)
-                columns.sort(cmp=lambda x,y:cmp(x.left, y.left))
+                columns.sort(key=lambda x: x.left)
         return columns
 
     def find_elements_in_row_of(self, x):
diff --git a/src/calibre/gui2/actions/choose_library.py b/src/calibre/gui2/actions/choose_library.py
index a8adb593e4..a562958470 100644
--- a/src/calibre/gui2/actions/choose_library.py
+++ b/src/calibre/gui2/actions/choose_library.py
@@ -51,8 +51,7 @@ class LibraryUsageStats(object):  # {{{
 
     def write_stats(self):
         locs = list(self.stats.keys())
-        locs.sort(cmp=lambda x, y: cmp(self.stats[x], self.stats[y]),
-                reverse=True)
+        locs.sort(key=lambda x: self.stats[x], reverse=True)
         for key in locs[500:]:
             self.stats.pop(key)
         gprefs.set('library_usage_stats', self.stats)
diff --git a/src/calibre/gui2/dialogs/catalog.py b/src/calibre/gui2/dialogs/catalog.py
index 1f32406b76..f10eab4384 100644
--- a/src/calibre/gui2/dialogs/catalog.py
+++ b/src/calibre/gui2/dialogs/catalog.py
@@ -93,7 +93,7 @@ class Catalog(QDialog, Ui_Dialog):
                 else:
                     info("No dynamic tab resources found for %s" % name)
 
-        self.widgets = sorted(self.widgets, cmp=lambda x,y:cmp(x.TITLE, y.TITLE))
+        self.widgets = sorted(self.widgets, key=lambda x: x.TITLE)
 
         # Generate a sorted list of installed catalog formats/sync_enabled pairs
         fmts = sorted([x[0] for x in self.fmts])
diff --git a/src/calibre/gui2/library/models.py b/src/calibre/gui2/library/models.py
index b36f91798c..d058e396e0 100644
--- a/src/calibre/gui2/library/models.py
+++ b/src/calibre/gui2/library/models.py
@@ -323,7 +323,7 @@ class BooksModel(QAbstractTableModel):  # {{{
                 return 100000
             return self.db.field_metadata[name]['rec_index']
 
-        self.column_map.sort(cmp=lambda x,y: cmp(col_idx(x), col_idx(y)))
+        self.column_map.sort(key=lambda x: col_idx(x))
         for col in self.column_map:
             if col in self.orig_headers:
                 self.headers[col] = self.orig_headers[col]
diff --git a/src/calibre/gui2/library/views.py b/src/calibre/gui2/library/views.py
index a49f7c778f..a5ce76815d 100644
--- a/src/calibre/gui2/library/views.py
+++ b/src/calibre/gui2/library/views.py
@@ -1031,7 +1031,7 @@ class BooksView(QTableView):  # {{{
                     h.visualIndex(x) > -1]
             if not pairs:
                 pairs = [(0, 0)]
-            pairs.sort(cmp=lambda x,y:cmp(x[1], y[1]))
+            pairs.sort(key=lambda x: x[1])
             i = pairs[0][0]
             index = self.model().index(row, i)
             if for_sync:
diff --git a/src/calibre/gui2/preferences/columns.py b/src/calibre/gui2/preferences/columns.py
index 0cd0fe5bea..3d346c41fb 100644
--- a/src/calibre/gui2/preferences/columns.py
+++ b/src/calibre/gui2/preferences/columns.py
@@ -69,7 +69,7 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         state = self.columns_state(defaults)
         self.hidden_cols = state['hidden_columns']
         positions = state['column_positions']
-        colmap.sort(cmp=lambda x,y: cmp(positions[x], positions[y]))
+        colmap.sort(key=lambda x: positions[x])
         self.opt_columns.clear()
 
         db = model.db
@@ -248,12 +248,10 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         if 'ondevice' in hidden_cols:
             hidden_cols.remove('ondevice')
 
-        def col_pos(x, y):
-            xidx = config_cols.index(x) if x in config_cols else sys.maxint
-            yidx = config_cols.index(y) if y in config_cols else sys.maxint
-            return cmp(xidx, yidx)
+        def col_pos(x):
+            return config_cols.index(x) if x in config_cols else sys.maxint
         positions = {}
-        for i, col in enumerate((sorted(model.column_map, cmp=col_pos))):
+        for i, col in enumerate((sorted(model.column_map, key=col_pos))):
             positions[col] = i
         state = {'hidden_columns': hidden_cols, 'column_positions':positions}
         self.gui.library_view.apply_state(state)
diff --git a/src/calibre/gui2/preferences/look_feel.py b/src/calibre/gui2/preferences/look_feel.py
index 0fb52d9a97..258ffcdc15 100644
--- a/src/calibre/gui2/preferences/look_feel.py
+++ b/src/calibre/gui2/preferences/look_feel.py
@@ -456,7 +456,7 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
                  if l != lang]
         if lang != 'en':
             items.append(('en', get_esc_lang('en')))
-        items.sort(cmp=lambda x, y: cmp(x[1].lower(), y[1].lower()))
+        items.sort(key=lambda x: x[1].lower())
         choices = [(y, x) for x, y in items]
         # Default language is the autodetected one
         choices = [(get_language(lang), lang)] + choices
diff --git a/src/calibre/gui2/preferences/main.py b/src/calibre/gui2/preferences/main.py
index 3b8cc99c45..43f4386d5b 100644
--- a/src/calibre/gui2/preferences/main.py
+++ b/src/calibre/gui2/preferences/main.py
@@ -171,7 +171,7 @@ class Browser(QScrollArea):  # {{{
         self.category_names = category_names
 
         categories = list(category_map.keys())
-        categories.sort(cmp=lambda x, y: cmp(category_map[x], category_map[y]))
+        categories.sort(key=lambda x: category_map[x])
 
         self.category_map = OrderedDict()
         for c in categories:
@@ -181,7 +181,7 @@ class Browser(QScrollArea):  # {{{
             self.category_map[plugin.category].append(plugin)
 
         for plugins in self.category_map.values():
-            plugins.sort(cmp=lambda x, y: cmp(x.name_order, y.name_order))
+            plugins.sort(key=lambda x: x.name_order)
 
         self.widgets = []
         self._layout = QVBoxLayout()
diff --git a/src/calibre/gui2/preferences/plugboard.py b/src/calibre/gui2/preferences/plugboard.py
index 5005e87735..65dea1c87d 100644
--- a/src/calibre/gui2/preferences/plugboard.py
+++ b/src/calibre/gui2/preferences/plugboard.py
@@ -34,17 +34,6 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         self.db = gui.library_view.model().db
 
     def initialize(self):
-        def field_cmp(x, y):
-            if x.startswith('#'):
-                if y.startswith('#'):
-                    return cmp(x.lower(), y.lower())
-                else:
-                    return 1
-            elif y.startswith('#'):
-                return -1
-            else:
-                return cmp(x.lower(), y.lower())
-
         ConfigWidgetBase.initialize(self)
 
         self.current_plugboards = copy.deepcopy(self.db.prefs.get('plugboards',{}))
@@ -73,7 +62,7 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
             if n not in self.disabled_devices:
                 self.disabled_devices.append(n)
 
-        self.devices.sort(cmp=lambda x, y: cmp(x.lower(), y.lower()))
+        self.devices.sort(key=lambda x: x.lower())
         self.devices.insert(1, plugboard_save_to_disk_value)
         self.devices.insert(1, plugboard_content_server_value)
         self.device_to_formats_map[plugboard_content_server_value] = \
diff --git a/src/calibre/gui2/preferences/plugins.py b/src/calibre/gui2/preferences/plugins.py
index a683eccf4d..c3c777f1e9 100644
--- a/src/calibre/gui2/preferences/plugins.py
+++ b/src/calibre/gui2/preferences/plugins.py
@@ -61,7 +61,7 @@ class PluginModel(QAbstractItemModel, AdaptSQP):  # {{{
         self.categories = sorted(self._data.keys())
 
         for plugins in self._data.values():
-            plugins.sort(cmp=lambda x, y: cmp(x.name.lower(), y.name.lower()))
+            plugins.sort(key=lambda x: x.name.lower())
 
     def universal_set(self):
         ans = set([])
diff --git a/src/calibre/gui2/wizard/__init__.py b/src/calibre/gui2/wizard/__init__.py
index ec61d6c0fe..e137babbbe 100644
--- a/src/calibre/gui2/wizard/__init__.py
+++ b/src/calibre/gui2/wizard/__init__.py
@@ -427,7 +427,7 @@ def get_manufacturers():
 
 def get_devices_of(manufacturer):
     ans = [d for d in get_devices() if d.manufacturer == manufacturer]
-    return sorted(ans, cmp=lambda x,y:cmp(x.name, y.name))
+    return sorted(ans, key=lambda x: x.name)
 
 
 class ManufacturerModel(QAbstractListModel):
@@ -682,7 +682,7 @@ class LibraryPage(QWizardPage, LibraryUI):
                  if l != lang]
         if lang != 'en':
             items.append(('en', get_esc_lang('en')))
-        items.sort(cmp=lambda x, y: cmp(x[1], y[1]))
+        items.sort(key=lambda x: x[1])
         for item in items:
             self.language.addItem(item[1], (item[0]))
         self.language.blockSignals(False)
diff --git a/src/calibre/library/custom_columns.py b/src/calibre/library/custom_columns.py
index 56e53ee91b..ad2ae31e39 100644
--- a/src/calibre/library/custom_columns.py
+++ b/src/calibre/library/custom_columns.py
@@ -216,7 +216,7 @@ class CustomColumns(object):
         if data['is_multiple'] and data['datatype'] == 'text':
             ans = ans.split(data['multiple_seps']['cache_to_list']) if ans else []
             if data['display'].get('sort_alpha', False):
-                ans.sort(cmp=lambda x,y:cmp(x.lower(), y.lower()))
+                ans.sort(key=lambda x:x.lower())
         return ans
 
     def get_custom_extra(self, idx, label=None, num=None, index_is_id=False):
@@ -243,7 +243,7 @@ class CustomColumns(object):
         if data['is_multiple'] and data['datatype'] == 'text':
             ans = ans.split(data['multiple_seps']['cache_to_list']) if ans else []
             if data['display'].get('sort_alpha', False):
-                ans.sort(cmp=lambda x,y:cmp(x.lower(), y.lower()))
+                ans.sort(key=lambda x: x.lower())
         if data['datatype'] != 'series':
             return (ans, None)
         ign,lt = self.custom_table_names(data['num'])
diff --git a/src/calibre/library/database.py b/src/calibre/library/database.py
index b303833439..8ce65a023e 100644
--- a/src/calibre/library/database.py
+++ b/src/calibre/library/database.py
@@ -1018,7 +1018,7 @@ ALTER TABLE books ADD COLUMN isbn TEXT DEFAULT "" COLLATE NOCASE;
         if not ans:
             return []
         ans = [id[0] for id in ans]
-        ans.sort(cmp=lambda x, y: cmp(self.series_index(x, True), self.series_index(y, True)))
+        ans.sort(key=lambda x: self.series_index(x, True))
         return ans
 
     def books_in_series_of(self, index, index_is_id=False):
diff --git a/src/calibre/utils/smtp.py b/src/calibre/utils/smtp.py
index d840cc4c37..8da8cc7bd2 100644
--- a/src/calibre/utils/smtp.py
+++ b/src/calibre/utils/smtp.py
@@ -98,8 +98,7 @@ def get_mx(host, verbose=0):
     if verbose:
         print('Find mail exchanger for', host)
     answers = list(dns.resolver.query(host, 'MX'))
-    answers.sort(cmp=lambda x, y: cmp(int(getattr(x, 'preference', sys.maxint)),
-                                      int(getattr(y, 'preference', sys.maxint))))
+    answers.sort(key=lambda x: int(getattr(x, 'preference', sys.maxint)))
     return [str(x.exchange) for x in answers if hasattr(x, 'exchange')]
 
 
diff --git a/src/calibre/web/feeds/news.py b/src/calibre/web/feeds/news.py
index f51f7e5a21..101e68b510 100644
--- a/src/calibre/web/feeds/news.py
+++ b/src/calibre/web/feeds/news.py
@@ -760,7 +760,7 @@ class BasicNewsRecipe(Recipe):
         in index are not in weights, they are assumed to have a weight of 0.
         '''
         weights = defaultdict(lambda: 0, weights)
-        index.sort(cmp=lambda x, y: cmp(weights[x], weights[y]))
+        index.sort(key=lambda x: weights[x])
         return index
 
     def parse_index(self):