[py3] Replace filter/lambda by list comprehensions

This is more idiomatic and avoids returning a list on Python 2 and
an iterator on Python 3.

django/core/management/commands/syncdb.py

@@ -75,7 +75,7 @@ class Command(NoArgsCommand):
                 (opts.auto_created and converter(opts.auto_created._meta.db_table) in tables))
 
         manifest = SortedDict(
-            (app_name, filter(model_installed, model_list))
+            (app_name, list(filter(model_installed, model_list)))
             for app_name, model_list in all_models
         )
 

django/db/models/options.py

@@ -387,7 +387,7 @@ class Options(object):
             predicates.append(lambda k, v: not k.field.rel.is_hidden())
         cache = (self._related_objects_proxy_cache if include_proxy_eq
                  else self._related_objects_cache)
-        return filter(lambda t: all([p(*t) for p in predicates]), cache.items())
+        return [t for t in cache.items() if all(p(*t) for p in predicates)]
 
     def _fill_related_objects_cache(self):
         cache = SortedDict()

django/db/models/query.py

@@ -1107,7 +1107,7 @@ class ValuesListQuerySet(ValuesQuerySet):
             # If a field list has been specified, use it. Otherwise, use the
             # full list of fields, including extras and aggregates.
             if self._fields:
-                fields = list(self._fields) + filter(lambda f: f not in self._fields, aggregate_names)
+                fields = list(self._fields) + [f for f in aggregate_names if f not in self._fields]
             else:
                 fields = names
 

django/utils/autoreload.py

@@ -54,7 +54,8 @@ _win = (sys.platform == "win32")
 
 def code_changed():
     global _mtimes, _win
-    for filename in filter(lambda v: v, map(lambda m: getattr(m, "__file__", None), sys.modules.values())):
+    filenames = [getattr(m, "__file__", None) for m in sys.modules.values()]
+    for filename in filter(None, filenames):
         if filename.endswith(".pyc") or filename.endswith(".pyo"):
             filename = filename[:-1]
         if filename.endswith("$py.class"):

django/utils/ipv6.py

@@ -263,6 +263,6 @@ def _is_shorthand_ip(ip_str):
     """
     if ip_str.count('::') == 1:
         return True
-    if filter(lambda x: len(x) < 4, ip_str.split(':')):
+    if any(len(x) < 4 for x in ip_str.split(':')):
         return True
     return False