diff --git a/django/forms/fields.py b/django/forms/fields.py
index bd62a57200..c95930a2d0 100644
--- a/django/forms/fields.py
+++ b/django/forms/fields.py
@@ -45,9 +45,9 @@ __all__ = (
 
 
 class Field(object):
-    widget = TextInput # Default widget to use when rendering this type of Field.
-    hidden_widget = HiddenInput # Default widget to use when rendering this as "hidden".
-    default_validators = [] # Default set of validators
+    widget = TextInput  # Default widget to use when rendering this type of Field.
+    hidden_widget = HiddenInput  # Default widget to use when rendering this as "hidden".
+    default_validators = []  # Default set of validators
     # Add an 'invalid' entry to default_error_message if you want a specific
     # field error message not raised by the field validators.
     default_error_messages = {
diff --git a/django/forms/forms.py b/django/forms/forms.py
index d9be2cd3f8..ddd51ffaae 100644
--- a/django/forms/forms.py
+++ b/django/forms/forms.py
@@ -120,7 +120,7 @@ class BaseForm(object):
         # Translators: This is the default suffix added to form field labels
         self.label_suffix = label_suffix if label_suffix is not None else _(':')
         self.empty_permitted = empty_permitted
-        self._errors = None # Stores the errors after clean() has been called.
+        self._errors = None  # Stores the errors after clean() has been called.
         self._changed_data = None
 
         # The base_fields class attribute is the *class-wide* definition of
@@ -176,7 +176,7 @@ class BaseForm(object):
 
     def _html_output(self, normal_row, error_row, row_ender, help_text_html, errors_on_separate_row):
         "Helper function for outputting HTML. Used by as_table(), as_ul(), as_p()."
-        top_errors = self.non_field_errors() # Errors that should be displayed above all fields.
+        top_errors = self.non_field_errors()  # Errors that should be displayed above all fields.
         output, hidden_fields = [], []
 
         for name, field in self.fields.items():
@@ -223,7 +223,7 @@ class BaseForm(object):
         if top_errors:
             output.insert(0, error_row % force_text(top_errors))
 
-        if hidden_fields: # Insert any hidden fields in the last row.
+        if hidden_fields:  # Insert any hidden fields in the last row.
             str_hidden = ''.join(hidden_fields)
             if output:
                 last_row = output[-1]
@@ -295,7 +295,7 @@ class BaseForm(object):
         self.cleaned_data.
         """
         self._errors = ErrorDict()
-        if not self.is_bound: # Stop further processing.
+        if not self.is_bound:  # Stop further processing.
             return
         self.cleaned_data = {}
         # If the form is permitted to be empty, and none of the form data has
diff --git a/django/forms/formsets.py b/django/forms/formsets.py
index 81e2e8781a..5b2efee82e 100644
--- a/django/forms/formsets.py
+++ b/django/forms/formsets.py
@@ -244,7 +244,7 @@ class BaseFormSet(object):
 
             def compare_ordering_key(k):
                 if k[1] is None:
-                    return (1, 0) # +infinity, larger than any number
+                    return (1, 0)  # +infinity, larger than any number
                 return (0, k[1])
             self._ordering.sort(key=compare_ordering_key)
         # Return a list of form.cleaned_data dicts in the order specified by
@@ -316,7 +316,7 @@ class BaseFormSet(object):
         self._errors = []
         self._non_form_errors = self.error_class()
 
-        if not self.is_bound: # Stop further processing.
+        if not self.is_bound:  # Stop further processing.
             return
         for i in range(0, self.total_form_count()):
             form = self.forms[i]
diff --git a/django/forms/widgets.py b/django/forms/widgets.py
index a3f69d86ae..55ccada4a1 100644
--- a/django/forms/widgets.py
+++ b/django/forms/widgets.py
@@ -161,8 +161,8 @@ class SubWidget(object):
         return self.parent_widget.render(*args)
 
 class Widget(six.with_metaclass(MediaDefiningClass)):
-    is_hidden = False          # Determines whether this corresponds to an <input type="hidden">.
-    needs_multipart_form = False # Determines does this widget need multipart form
+    is_hidden = False             # Determines whether this corresponds to an <input type="hidden">.
+    needs_multipart_form = False  # Determines does this widget need multipart form
     is_localized = False
     is_required = False
 
@@ -227,7 +227,7 @@ class Input(Widget):
     Base class for all <input> widgets (except type='checkbox' and
     type='radio', which are special).
     """
-    input_type = None # Subclasses must define this.
+    input_type = None  # Subclasses must define this.
 
     def _format_value(self, value):
         if self.is_localized:
@@ -643,7 +643,7 @@ class ChoiceFieldRenderer(object):
         self.choices = choices
 
     def __getitem__(self, idx):
-        choice = self.choices[idx] # Let the IndexError propogate
+        choice = self.choices[idx]  # Let the IndexError propogate
         return self.choice_input_class(self.name, self.value, self.attrs.copy(), choice, idx)
 
     def __str__(self):
diff --git a/django/template/base.py b/django/template/base.py
index 2979f2a8f1..5f6cac1c6f 100644
--- a/django/template/base.py
+++ b/django/template/base.py
@@ -246,9 +246,9 @@ class Parser(object):
         while self.tokens:
             token = self.next_token()
             # Use the raw values here for TOKEN_* for a tiny performance boost.
-            if token.token_type == 0: # TOKEN_TEXT
+            if token.token_type == 0:  # TOKEN_TEXT
                 self.extend_nodelist(nodelist, TextNode(token.contents), token)
-            elif token.token_type == 1: # TOKEN_VAR
+            elif token.token_type == 1:  # TOKEN_VAR
                 if not token.contents:
                     self.empty_variable(token)
                 try:
@@ -258,7 +258,7 @@ class Parser(object):
                         raise
                 var_node = self.create_variable_node(filter_expression)
                 self.extend_nodelist(nodelist, var_node, token)
-            elif token.token_type == 2: # TOKEN_BLOCK
+            elif token.token_type == 2:  # TOKEN_BLOCK
                 try:
                     command = token.contents.split()[0]
                 except IndexError:
@@ -772,12 +772,12 @@ class Variable(object):
                     elif getattr(current, 'alters_data', False):
                         current = settings.TEMPLATE_STRING_IF_INVALID
                     else:
-                        try: # method call (assuming no args required)
+                        try:  # method call (assuming no args required)
                             current = current()
                         except TypeError:
                             try:
                                 getcallargs(current)
-                            except TypeError: # arguments *were* required
+                            except TypeError:  # arguments *were* required
                                 current = settings.TEMPLATE_STRING_IF_INVALID  # invalid method call
                             else:
                                 raise
diff --git a/django/template/defaultfilters.py b/django/template/defaultfilters.py
index 6e424fc6cb..bb3c9b320f 100644
--- a/django/template/defaultfilters.py
+++ b/django/template/defaultfilters.py
@@ -261,8 +261,8 @@ def truncatechars(value, arg):
     """
     try:
         length = int(arg)
-    except ValueError: # Invalid literal for int().
-        return value # Fail silently.
+    except ValueError:  # Invalid literal for int().
+        return value  # Fail silently.
     return Truncator(value).chars(length)
 
 @register.filter(is_safe=True)
@@ -277,8 +277,8 @@ def truncatewords(value, arg):
     """
     try:
         length = int(arg)
-    except ValueError: # Invalid literal for int().
-        return value # Fail silently.
+    except ValueError:  # Invalid literal for int().
+        return value  # Fail silently.
     return Truncator(value).words(length, truncate=' ...')
 
 @register.filter(is_safe=True)
@@ -293,8 +293,8 @@ def truncatewords_html(value, arg):
     """
     try:
         length = int(arg)
-    except ValueError: # invalid literal for int()
-        return value # Fail silently.
+    except ValueError:  # invalid literal for int()
+        return value  # Fail silently.
     return Truncator(value).words(length, html=True, truncate=' ...')
 
 @register.filter(is_safe=False)
@@ -511,7 +511,7 @@ def join(value, arg, autoescape=None):
         value = [conditional_escape(v) for v in value]
     try:
         data = conditional_escape(arg).join(value)
-    except AttributeError: # fail silently but nicely
+    except AttributeError:  # fail silently but nicely
         return value
     return mark_safe(data)
 
@@ -563,7 +563,7 @@ def slice_filter(value, arg):
         return value[slice(*bits)]
 
     except (ValueError, TypeError):
-        return value # Fail silently.
+        return value  # Fail silently.
 
 @register.filter(is_safe=True, needs_autoescape=True)
 def unordered_list(value, autoescape=None):
@@ -681,7 +681,7 @@ def get_digit(value, arg):
         arg = int(arg)
         value = int(value)
     except ValueError:
-        return value # Fail silently for an invalid argument
+        return value  # Fail silently for an invalid argument
     if arg < 1:
         return value
     try:
@@ -786,7 +786,7 @@ def yesno(value, arg=None):
         arg = ugettext('yes,no,maybe')
     bits = arg.split(',')
     if len(bits) < 2:
-        return value # Invalid arg.
+        return value  # Invalid arg.
     try:
         yes, no, maybe = bits
     except ValueError:
@@ -871,13 +871,13 @@ def pluralize(value, arg='s'):
     try:
         if int(value) != 1:
             return plural_suffix
-    except ValueError: # Invalid string that's not a number.
+    except ValueError:  # Invalid string that's not a number.
         pass
-    except TypeError: # Value isn't a string or a number; maybe it's a list?
+    except TypeError:  # Value isn't a string or a number; maybe it's a list?
         try:
             if len(value) != 1:
                 return plural_suffix
-        except TypeError: # len() of unsized object.
+        except TypeError:  # len() of unsized object.
             pass
     return singular_suffix
 
diff --git a/django/template/defaulttags.py b/django/template/defaulttags.py
index bc9cfc1c8f..2822c3d362 100644
--- a/django/template/defaulttags.py
+++ b/django/template/defaulttags.py
@@ -347,7 +347,7 @@ class SsiNode(Node):
             if settings.DEBUG:
                 return "[Didn't have permission to include file]"
             else:
-                return '' # Fail silently for invalid includes.
+                return ''  # Fail silently for invalid includes.
         try:
             with open(filepath, 'r') as fp:
                 output = fp.read()
@@ -361,7 +361,7 @@ class SsiNode(Node):
                 if settings.DEBUG:
                     return "[Included template had syntax error: %s]" % e
                 else:
-                    return '' # Fail silently for invalid included templates.
+                    return ''  # Fail silently for invalid included templates.
         return output
 
 class LoadNode(Node):
@@ -860,7 +860,7 @@ def ifnotequal(parser, token):
 class TemplateLiteral(Literal):
     def __init__(self, value, text):
         self.value = value
-        self.text = text # for better error messages
+        self.text = text  # for better error messages
 
     def display(self):
         return self.text
diff --git a/django/template/loader_tags.py b/django/template/loader_tags.py
index 28b948174f..c6bb3acadf 100644
--- a/django/template/loader_tags.py
+++ b/django/template/loader_tags.py
@@ -93,7 +93,7 @@ class ExtendsNode(Node):
                     self.parent_name.token
             raise TemplateSyntaxError(error_msg)
         if hasattr(parent, 'render'):
-            return parent # parent is a Template object
+            return parent  # parent is a Template object
         return get_template(parent)
 
     def render(self, context):
@@ -165,7 +165,7 @@ def do_block(parser, token):
         if block_name in parser.__loaded_blocks:
             raise TemplateSyntaxError("'%s' tag with name '%s' appears more than once" % (bits[0], block_name))
         parser.__loaded_blocks.append(block_name)
-    except AttributeError: # parser.__loaded_blocks isn't a list yet
+    except AttributeError:  # parser.__loaded_blocks isn't a list yet
         parser.__loaded_blocks = [block_name]
     nodelist = parser.parse(('endblock',))
 
diff --git a/django/template/smartif.py b/django/template/smartif.py
index e2ca3959a2..7cf1c6a023 100644
--- a/django/template/smartif.py
+++ b/django/template/smartif.py
@@ -13,9 +13,9 @@ class TokenBase(object):
     Base class for operators and literals, mainly for debugging and for throwing
     syntax errors.
     """
-    id = None # node/token type name
-    value = None # used by literals
-    first = second = None # used by tree nodes
+    id = None  # node/token type name
+    value = None  # used by literals
+    first = second = None  # used by tree nodes
 
     def nud(self, parser):
         # Null denotation - called in prefix context
@@ -159,7 +159,7 @@ class IfParser(object):
             token = tokens[i]
             if token == "not" and i + 1 < l and tokens[i+1] == "in":
                 token = "not in"
-                i += 1 # skip 'in'
+                i += 1  # skip 'in'
             mapped_tokens.append(self.translate_token(token))
             i += 1
 
diff --git a/django/utils/autoreload.py b/django/utils/autoreload.py
index 70fe508284..fed2fd84b8 100644
--- a/django/utils/autoreload.py
+++ b/django/utils/autoreload.py
@@ -257,7 +257,7 @@ def reloader_thread():
         fn = code_changed
     while RUN_RELOADER:
         if fn():
-            sys.exit(3) # force reload
+            sys.exit(3)  # force reload
         time.sleep(1)
 
 
diff --git a/django/utils/cache.py b/django/utils/cache.py
index f74056cafa..0d664afdf4 100644
--- a/django/utils/cache.py
+++ b/django/utils/cache.py
@@ -112,7 +112,7 @@ def patch_response_headers(response, cache_timeout=None):
     if cache_timeout is None:
         cache_timeout = settings.CACHE_MIDDLEWARE_SECONDS
     if cache_timeout < 0:
-        cache_timeout = 0 # Can't have max-age negative
+        cache_timeout = 0  # Can't have max-age negative
     if settings.USE_ETAGS and not response.has_header('ETag'):
         if hasattr(response, 'render') and callable(response.render):
             response.add_post_render_callback(_set_response_etag)
diff --git a/django/utils/checksums.py b/django/utils/checksums.py
index 7bd21c95e0..1113f3b796 100644
--- a/django/utils/checksums.py
+++ b/django/utils/checksums.py
@@ -6,7 +6,7 @@ __all__ = ['luhn']
 
 from django.utils import six
 
-LUHN_ODD_LOOKUP = (0, 2, 4, 6, 8, 1, 3, 5, 7, 9) # sum_of_digits(index * 2)
+LUHN_ODD_LOOKUP = (0, 2, 4, 6, 8, 1, 3, 5, 7, 9)  # sum_of_digits(index * 2)
 
 def luhn(candidate):
     """
diff --git a/django/utils/dateformat.py b/django/utils/dateformat.py
index 2fe6760a88..27413a2e67 100644
--- a/django/utils/dateformat.py
+++ b/django/utils/dateformat.py
@@ -267,7 +267,7 @@ class DateFormat(TimeFormat):
 
     def S(self):
         "English ordinal suffix for the day of the month, 2 characters; i.e. 'st', 'nd', 'rd' or 'th'"
-        if self.data.day in (11, 12, 13): # Special case
+        if self.data.day in (11, 12, 13):  # Special case
             return 'th'
         last = self.data.day % 10
         if last == 1:
diff --git a/django/utils/dates.py b/django/utils/dates.py
index 37746294b8..25f092e618 100644
--- a/django/utils/dates.py
+++ b/django/utils/dates.py
@@ -27,7 +27,7 @@ MONTHS_3_REV = {
     'jan': 1, 'feb': 2, 'mar': 3, 'apr': 4, 'may': 5, 'jun': 6, 'jul': 7, 'aug': 8,
     'sep': 9, 'oct': 10, 'nov': 11, 'dec': 12
 }
-MONTHS_AP = { # month names in Associated Press style
+MONTHS_AP = {  # month names in Associated Press style
     1: pgettext_lazy('abbrev. month', 'Jan.'),
     2: pgettext_lazy('abbrev. month', 'Feb.'),
     3: pgettext_lazy('abbrev. month', 'March'),
@@ -41,7 +41,7 @@ MONTHS_AP = { # month names in Associated Press style
     11: pgettext_lazy('abbrev. month', 'Nov.'),
     12: pgettext_lazy('abbrev. month', 'Dec.')
 }
-MONTHS_ALT = { # required for long date representation by some locales
+MONTHS_ALT = {  # required for long date representation by some locales
     1: pgettext_lazy('alt. month', 'January'),
     2: pgettext_lazy('alt. month', 'February'),
     3: pgettext_lazy('alt. month', 'March'),
diff --git a/django/utils/dictconfig.py b/django/utils/dictconfig.py
index c676035dc7..d01b785001 100644
--- a/django/utils/dictconfig.py
+++ b/django/utils/dictconfig.py
@@ -210,7 +210,7 @@ class BaseConfigurator(object):
                             d = d[idx]
                         else:
                             try:
-                                n = int(idx) # try as number first (most likely)
+                                n = int(idx)  # try as number first (most likely)
                                 d = d[n]
                             except TypeError:
                                 d = d[idx]
@@ -238,7 +238,7 @@ class BaseConfigurator(object):
                  isinstance(value, tuple):
             value = ConvertingTuple(value)
             value.configurator = self
-        elif isinstance(value, six.string_types): # str for py3k
+        elif isinstance(value, six.string_types):  # str for py3k
             m = self.CONVERT_PATTERN.match(value)
             if m:
                 d = m.groupdict()
@@ -385,7 +385,7 @@ class DictConfigurator(BaseConfigurator):
                         prefixed = name + "."
                         pflen = len(prefixed)
                         num_existing = len(existing)
-                        i = i + 1 # look at the entry after name
+                        i = i + 1  # look at the entry after name
                         while (i < num_existing) and\
                               (existing[i][:pflen] == prefixed):
                             child_loggers.append(existing[i])
@@ -425,7 +425,7 @@ class DictConfigurator(BaseConfigurator):
     def configure_formatter(self, config):
         """Configure a formatter from a dictionary."""
         if '()' in config:
-            factory = config['()'] # for use in exception handler
+            factory = config['()']  # for use in exception handler
             try:
                 result = self.configure_custom(config)
             except TypeError as te:
diff --git a/django/utils/html.py b/django/utils/html.py
index 81b06efeef..5b2416f03f 100644
--- a/django/utils/html.py
+++ b/django/utils/html.py
@@ -175,8 +175,8 @@ def smart_urlquote(url):
     try:
         scheme, netloc, path, query, fragment = urlsplit(url)
         try:
-            netloc = netloc.encode('idna').decode('ascii') # IDN -> ACE
-        except UnicodeError: # invalid domain part
+            netloc = netloc.encode('idna').decode('ascii')  # IDN -> ACE
+        except UnicodeError:  # invalid domain part
             pass
         else:
             url = urlunsplit((scheme, netloc, path, query, fragment))
diff --git a/django/utils/html_parser.py b/django/utils/html_parser.py
index 2a408e9f55..fe71172cfd 100644
--- a/django/utils/html_parser.py
+++ b/django/utils/html_parser.py
@@ -84,22 +84,22 @@ else:
             else:
                 self.handle_starttag(tag, attrs)
                 if tag in self.CDATA_CONTENT_ELEMENTS:
-                    self.set_cdata_mode(tag) # <--------------------------- Changed
+                    self.set_cdata_mode(tag)  # <--------------------------- Changed
             return endpos
 
         # Internal -- parse endtag, return end or -1 if incomplete
         def parse_endtag(self, i):
             rawdata = self.rawdata
             assert rawdata[i:i + 2] == "</", "unexpected call to parse_endtag"
-            match = _html_parser.endendtag.search(rawdata, i + 1) # >
+            match = _html_parser.endendtag.search(rawdata, i + 1)  # >
             if not match:
                 return -1
             j = match.end()
-            match = _html_parser.endtagfind.match(rawdata, i) # </ + tag + >
+            match = _html_parser.endtagfind.match(rawdata, i)  # </ + tag + >
             if not match:
-                if self.cdata_tag is not None: # *** add ***
-                    self.handle_data(rawdata[i:j]) # *** add ***
-                    return j # *** add ***
+                if self.cdata_tag is not None:  # *** add ***
+                    self.handle_data(rawdata[i:j])  # *** add ***
+                    return j  # *** add ***
                 self.error("bad end tag: %r" % (rawdata[i:j],))
             # --- changed start ---------------------------------------------------
             tag = match.group(1).strip()
diff --git a/django/utils/http.py b/django/utils/http.py
index 897b1456c4..413ac72a08 100644
--- a/django/utils/http.py
+++ b/django/utils/http.py
@@ -211,7 +211,7 @@ def urlsafe_base64_decode(s):
     Decodes a base64 encoded string, adding back any trailing equal signs that
     might have been stripped.
     """
-    s = s.encode('utf-8') # base64encode should only return ASCII.
+    s = s.encode('utf-8')  # base64encode should only return ASCII.
     try:
         return base64.urlsafe_b64decode(s.ljust(len(s) + len(s) % 4, b'='))
     except (LookupError, BinasciiError) as e: