Merged revisions 56125-56153 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/branches/p3yk

........
  r56127 | georg.brandl | 2007-06-30 09:32:49 +0200 (Sat, 30 Jun 2007) | 2 lines

  Fix a place where floor division would be in order.
........
  r56135 | guido.van.rossum | 2007-07-01 06:13:54 +0200 (Sun, 01 Jul 2007) | 28 lines

  Make map() and filter() identical to itertools.imap() and .ifilter(),
  respectively.

  I fixed two bootstrap issues, due to the dynamic import of itertools:

  1. Starting python requires that map() and filter() are not used until
     site.py has added build/lib.<arch> to sys.path.
  2. Building python requires that setup.py and distutils and everything
     they use is free of map() and filter() calls.

  Beyond this, I only fixed the tests in test_builtin.py.
  Others, please help fixing the remaining tests that are now broken!
  The fixes are usually simple:
  a. map(None, X) -> list(X)
  b. map(F, X) -> list(map(F, X))
  c. map(lambda x: F(x), X) -> [F(x) for x in X]
  d. filter(F, X) -> list(filter(F, X))
  e. filter(lambda x: P(x), X) -> [x for x in X if P(x)]

  Someone, please also contribute a fixer for 2to3 to do this.
  It can leave map()/filter() calls alone that are already
  inside a list() or sorted() call or for-loop.

  Only in rare cases have I seen code that depends on map() of lists
  of different lengths going to the end of the longest, or on filter()
  of a string or tuple returning an object of the same type; these
  will need more thought to fix.
........
  r56136 | guido.van.rossum | 2007-07-01 06:22:01 +0200 (Sun, 01 Jul 2007) | 3 lines

  Make it so that test_decimal fails instead of hangs, to help automated
  test runners.
........
  r56139 | georg.brandl | 2007-07-01 18:20:58 +0200 (Sun, 01 Jul 2007) | 2 lines

  Fix a few test cases after the map->imap change.
........
  r56142 | neal.norwitz | 2007-07-02 06:38:12 +0200 (Mon, 02 Jul 2007) | 1 line

  Get a bunch more tests passing after converting map/filter to return iterators.
........
  r56147 | guido.van.rossum | 2007-07-02 15:32:02 +0200 (Mon, 02 Jul 2007) | 4 lines

  Fix the remaining failing unit tests (at least on OSX).
  Also tweaked urllib2 so it doesn't raise socket.gaierror when
  all network interfaces are turned off.
........

45 files changed, 229 insertions, 758 deletions

diff --git a/Lib/cgi.py b/Lib/cgi.py
index f756330fc9..ab126d53bd 100755
--- a/Lib/cgi.py
+++ b/Lib/cgi.py
@@ -572,7 +572,7 @@ class FieldStorage:
         if key in self:
             value = self[key]
             if type(value) is type([]):
-                return map(attrgetter('value'), value)
+                return [x.value for x in value]
             else:
                 return value.value
         else:
@@ -594,7 +594,7 @@ class FieldStorage:
         if key in self:
             value = self[key]
             if type(value) is type([]):
-                return map(attrgetter('value'), value)
+                return [x.value for x in value]
             else:
                 return [value.value]
         else:
diff --git a/Lib/csv.py b/Lib/csv.py
index 758c79a4d8..cd0f7d34ba 100644
--- a/Lib/csv.py
+++ b/Lib/csv.py
@@ -253,7 +253,7 @@ class Sniffer:
         additional chunks as necessary.
         """
 
-        data = filter(None, data.split('\n'))
+        data = list(filter(None, data.split('\n')))
 
         ascii = [chr(c) for c in range(127)] # 7-bit ASCII
 
diff --git a/Lib/decimal.py b/Lib/decimal.py
index 2611f79789..17d67d541d 100644
--- a/Lib/decimal.py
+++ b/Lib/decimal.py
@@ -841,7 +841,7 @@ class Decimal(object):
         if context is None:
             context = getcontext()
 
-        tmp = map(str, self._int)
+        tmp = list(map(str, self._int))
         numdigits = len(self._int)
         leftdigits = self._exp + numdigits
         if eng and not self:  # self = 0eX wants 0[.0[0]]eY, not [[0]0]0eY
@@ -1193,7 +1193,9 @@ class Decimal(object):
         op1 = _WorkRep(self)
         op2 = _WorkRep(other)
 
-        ans = Decimal((resultsign, map(int, str(op1.int * op2.int)), resultexp))
+        ans = Decimal((resultsign,
+                       tuple(map(int, str(op1.int * op2.int))),
+                       resultexp))
         if shouldround:
             ans = ans._fix(context)
 
@@ -3145,7 +3147,7 @@ def _string2exact(s):
     exp -= len(fracpart)
 
     mantissa = intpart + fracpart
-    tmp = map(int, mantissa)
+    tmp = list(map(int, mantissa))
     backup = tmp
     while tmp and tmp[0] == 0:
         del tmp[0]
diff --git a/Lib/difflib.py b/Lib/difflib.py
index f992650310..13704158b4 100644
--- a/Lib/difflib.py
+++ b/Lib/difflib.py
@@ -587,7 +587,7 @@ class SequenceMatcher:
         Each group is in the same format as returned by get_opcodes().
 
         >>> from pprint import pprint
-        >>> a = map(str, range(1,40))
+        >>> a = list(map(str, range(1,40)))
         >>> b = a[:]
         >>> b[8:8] = ['i']     # Make an insertion
         >>> b[20] += 'x'       # Make a replacement
diff --git a/Lib/distutils/dist.py b/Lib/distutils/dist.py
index c01724d83a..8f614765ef 100644
--- a/Lib/distutils/dist.py
+++ b/Lib/distutils/dist.py
@@ -112,8 +112,7 @@ Common commands: (see '--help-commands' for more)
         ('obsoletes', None,
          "print the list of packages/modules made obsolete")
         ]
-    display_option_names = map(lambda x: translate_longopt(x[0]),
-                               display_options)
+    display_option_names = [translate_longopt(x[0]) for x in display_options]
 
     # negative options are options that exclude other options
     negative_opt = {'quiet': 'verbose'}
@@ -805,7 +804,7 @@ Common commands: (see '--help-commands' for more)
             pkgs = (pkgs or "").split(",")
             for i in range(len(pkgs)):
                 pkgs[i] = pkgs[i].strip()
-            pkgs = filter(None, pkgs)
+            pkgs = [p for p in pkgs if p]
             if "distutils.command" not in pkgs:
                 pkgs.insert(0, "distutils.command")
             self.command_packages = pkgs
diff --git a/Lib/distutils/sysconfig.py b/Lib/distutils/sysconfig.py
index 51f23a24a5..346707fa90 100644
--- a/Lib/distutils/sysconfig.py
+++ b/Lib/distutils/sysconfig.py
@@ -372,7 +372,7 @@ def _init_posix():
         if cur_target == '':
             cur_target = cfg_target
             os.putenv('MACOSX_DEPLOYMENT_TARGET', cfg_target)
-        elif map(int, cfg_target.split('.')) > map(int, cur_target.split('.')):
+        elif [int(x) for x in cfg_target.split('.')] > [int(x) for x in cur_target.split('.')]:
             my_msg = ('$MACOSX_DEPLOYMENT_TARGET mismatch: now "%s" but "%s" during configure'
                 % (cur_target, cfg_target))
             raise DistutilsPlatformError(my_msg)
diff --git a/Lib/distutils/version.py b/Lib/distutils/version.py
index 2db6b18f1e..de20e21f70 100644
--- a/Lib/distutils/version.py
+++ b/Lib/distutils/version.py
@@ -148,7 +148,7 @@ class StrictVersion (Version):
         if patch:
             self.version = tuple(map(int, [major, minor, patch]))
         else:
-            self.version = tuple(map(int, [major, minor]) + [0])
+            self.version = tuple(map(int, [major, minor])) + (0,)
 
         if prerelease:
             self.prerelease = (prerelease[0], int(prerelease_num))
diff --git a/Lib/encodings/idna.py b/Lib/encodings/idna.py
index 55e1643c25..b81e5fa158 100644
--- a/Lib/encodings/idna.py
+++ b/Lib/encodings/idna.py
@@ -38,7 +38,7 @@ def nameprep(label):
             raise UnicodeError("Invalid character %r" % c)
 
     # Check bidi
-    RandAL = map(stringprep.in_table_d1, label)
+    RandAL = [stringprep.in_table_d1(x) for x in label]
     for c in RandAL:
         if c:
             # There is a RandAL char in the string. Must perform further
@@ -47,7 +47,7 @@ def nameprep(label):
             # This is table C.8, which was already checked
             # 2) If a string contains any RandALCat character, the string
             # MUST NOT contain any LCat character.
-            if filter(stringprep.in_table_d2, label):
+            if any(stringprep.in_table_d2(x) for x in label):
                 raise UnicodeError("Violation of BIDI requirement 2")
 
             # 3) If a string contains any RandALCat character, a
diff --git a/Lib/filecmp.py b/Lib/filecmp.py
index 9c0ce5a851..ac01613479 100644
--- a/Lib/filecmp.py
+++ b/Lib/filecmp.py
@@ -132,9 +132,9 @@ class dircmp:
     def phase1(self): # Compute common names
         a = dict(izip(imap(os.path.normcase, self.left_list), self.left_list))
         b = dict(izip(imap(os.path.normcase, self.right_list), self.right_list))
-        self.common = map(a.__getitem__, ifilter(b.__contains__, a))
-        self.left_only = map(a.__getitem__, ifilterfalse(b.__contains__, a))
-        self.right_only = map(b.__getitem__, ifilterfalse(a.__contains__, b))
+        self.common = list(map(a.__getitem__, ifilter(b.__contains__, a)))
+        self.left_only = list(map(a.__getitem__, ifilterfalse(b.__contains__, a)))
+        self.right_only = list(map(b.__getitem__, ifilterfalse(a.__contains__, b)))
 
     def phase2(self): # Distinguish files, directories, funnies
         self.common_dirs = []
diff --git a/Lib/heapq.py b/Lib/heapq.py
index f64d8ba862..f3d0669934 100644
--- a/Lib/heapq.py
+++ b/Lib/heapq.py
@@ -129,7 +129,7 @@ From all times, sorting has always been a Great Art! :-)
 __all__ = ['heappush', 'heappop', 'heapify', 'heapreplace', 'merge',
            'nlargest', 'nsmallest']
 
-from itertools import islice, repeat, count, imap, izip, tee
+from itertools import islice, repeat, count, izip, tee
 from operator import itemgetter, neg
 import bisect
 
@@ -225,7 +225,7 @@ def nsmallest(n, iterable):
     #    O(m) + O(n log m) comparisons.
     h = list(iterable)
     heapify(h)
-    return map(heappop, repeat(h, min(n, len(h))))
+    return list(map(heappop, repeat(h, min(n, len(h)))))
 
 # 'heap' is a heap at all indices >= startpos, except possibly for pos.  pos
 # is the index of a leaf with a possibly out-of-order value.  Restore the
@@ -351,9 +351,9 @@ def nsmallest(n, iterable, key=None):
     Equivalent to:  sorted(iterable, key=key)[:n]
     """
     in1, in2 = tee(iterable)
-    it = izip(imap(key, in1), count(), in2)                 # decorate
+    it = izip(map(key, in1), count(), in2)                  # decorate
     result = _nsmallest(n, it)
-    return map(itemgetter(2), result)                       # undecorate
+    return list(map(itemgetter(2), result))                 # undecorate
 
 _nlargest = nlargest
 def nlargest(n, iterable, key=None):
@@ -362,9 +362,9 @@ def nlargest(n, iterable, key=None):
     Equivalent to:  sorted(iterable, key=key, reverse=True)[:n]
     """
     in1, in2 = tee(iterable)
-    it = izip(imap(key, in1), imap(neg, count()), in2)      # decorate
+    it = izip(map(key, in1), map(neg, count()), in2)        # decorate
     result = _nlargest(n, it)
-    return map(itemgetter(2), result)                       # undecorate
+    return list(map(itemgetter(2), result))                 # undecorate
 
 if __name__ == "__main__":
     # Simple sanity test
diff --git a/Lib/logging/config.py b/Lib/logging/config.py
index 0bf79a5a20..99755e2ec9 100644
--- a/Lib/logging/config.py
+++ b/Lib/logging/config.py
@@ -176,7 +176,7 @@ def _install_loggers(cp, handlers):
     # configure the root first
     llist = cp.get("loggers", "keys")
     llist = llist.split(",")
-    llist = map(lambda x: x.strip(), llist)
+    llist = list(map(lambda x: x.strip(), llist))
     llist.remove("root")
     sectname = "logger_root"
     root = logging.root
diff --git a/Lib/mhlib.py b/Lib/mhlib.py
index 4b32020912..c06e1a6566 100644
--- a/Lib/mhlib.py
+++ b/Lib/mhlib.py
@@ -282,8 +282,7 @@ class Folder:
         for name in os.listdir(self.getfullname()):
             if match(name):
                 append(name)
-        messages = map(int, messages)
-        messages.sort()
+        messages = sorted(map(int, messages))
         if messages:
             self.last = messages[-1]
         else:
diff --git a/Lib/optparse.py b/Lib/optparse.py
index ed51b93820..e648a281e4 100644
--- a/Lib/optparse.py
+++ b/Lib/optparse.py
@@ -573,7 +573,7 @@ class Option:
         # Filter out None because early versions of Optik had exactly
         # one short option and one long option, either of which
         # could be None.
-        opts = filter(None, opts)
+        opts = [opt for opt in opts if opt]
         if not opts:
             raise TypeError("at least one option string must be supplied")
         return opts
diff --git a/Lib/pydoc.py b/Lib/pydoc.py
index 45943334dd..3b3f1bd959 100755
--- a/Lib/pydoc.py
+++ b/Lib/pydoc.py
@@ -468,9 +468,9 @@ class HTMLDoc(Doc):
     def multicolumn(self, list, format, cols=4):
         """Format a list of items into a multi-column list."""
         result = ''
-        rows = (len(list)+cols-1)/cols
+        rows = (len(list)+cols-1)//cols
         for col in range(cols):
-            result = result + '<td width="%d%%" valign=top>' % (100/cols)
+            result = result + '<td width="%d%%" valign=top>' % (100//cols)
             for i in range(rows*col, rows*col+rows):
                 if i < len(list):
                     result = result + format(list[i]) + '<br>\n'
diff --git a/Lib/string.py b/Lib/string.py
index fd8e91be73..51b2067ab9 100644
--- a/Lib/string.py
+++ b/Lib/string.py
@@ -30,9 +30,7 @@ printable = digits + letters + punctuation + whitespace
 
 # Case conversion helpers
 # Use str to convert Unicode literal in case of -U
-l = map(chr, range(256))
-_idmap = str('').join(l)
-del l
+_idmap = str('').join(chr(c) for c in range(256))
 
 # Functions which aren't available as string methods.
 
@@ -63,11 +61,10 @@ def maketrans(fromstr, tostr):
         raise ValueError, "maketrans arguments must have same length"
     global _idmapL
     if not _idmapL:
-        _idmapL = map(None, _idmap)
+        _idmapL = list(_idmap)
     L = _idmapL[:]
-    fromstr = map(ord, fromstr)
-    for i in range(len(fromstr)):
-        L[fromstr[i]] = tostr[i]
+    for i, c in enumerate(fromstr):
+        L[ord(c)] = tostr[i]
     return ''.join(L)
 
 
diff --git a/Lib/test/test_bisect.py b/Lib/test/test_bisect.py
index 0baeb1414f..95eafbe06b 100644
--- a/Lib/test/test_bisect.py
+++ b/Lib/test/test_bisect.py
@@ -223,7 +223,7 @@ This example uses bisect() to look up a letter grade for an exam total
     ...
     >>> grade(66)
     'C'
-    >>> map(grade, [33, 99, 77, 44, 12, 88])
+    >>> list(map(grade, [33, 99, 77, 44, 12, 88]))
     ['E', 'A', 'B', 'D', 'F', 'A']
 
 """
diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py
index a2fde023e3..036a9f274f 100644
--- a/Lib/test/test_builtin.py
+++ b/Lib/test/test_builtin.py
@@ -466,11 +466,11 @@ class BuiltinTest(unittest.TestCase):
         self.assertEqual((g, l), ({'a': 1}, {'b': 2}))
 
     def test_filter(self):
-        self.assertEqual(filter(lambda c: 'a' <= c <= 'z', 'Hello World'), 'elloorld')
-        self.assertEqual(filter(None, [1, 'hello', [], [3], '', None, 9, 0]), [1, 'hello', [3], 9])
-        self.assertEqual(filter(lambda x: x > 0, [1, -3, 9, 0, 2]), [1, 9, 2])
-        self.assertEqual(filter(None, Squares(10)), [1, 4, 9, 16, 25, 36, 49, 64, 81])
-        self.assertEqual(filter(lambda x: x%2, Squares(10)), [1, 9, 25, 49, 81])
+        self.assertEqual(list(filter(lambda c: 'a' <= c <= 'z', 'Hello World')), list('elloorld'))
+        self.assertEqual(list(filter(None, [1, 'hello', [], [3], '', None, 9, 0])), [1, 'hello', [3], 9])
+        self.assertEqual(list(filter(lambda x: x > 0, [1, -3, 9, 0, 2])), [1, 9, 2])
+        self.assertEqual(list(filter(None, Squares(10))), [1, 4, 9, 16, 25, 36, 49, 64, 81])
+        self.assertEqual(list(filter(lambda x: x%2, Squares(10))), [1, 9, 25, 49, 81])
         def identity(item):
             return 1
         filter(identity, Squares(5))
@@ -480,67 +480,15 @@ class BuiltinTest(unittest.TestCase):
                 if index<4:
                     return 42
                 raise ValueError
-        self.assertRaises(ValueError, filter, lambda x: x, BadSeq())
+        self.assertRaises(ValueError, list, filter(lambda x: x, BadSeq()))
         def badfunc():
             pass
-        self.assertRaises(TypeError, filter, badfunc, range(5))
+        self.assertRaises(TypeError, list, filter(badfunc, range(5)))
 
         # test bltinmodule.c::filtertuple()
-        self.assertEqual(filter(None, (1, 2)), (1, 2))
-        self.assertEqual(filter(lambda x: x>=3, (1, 2, 3, 4)), (3, 4))
-        self.assertRaises(TypeError, filter, 42, (1, 2))
-
-        # test bltinmodule.c::filterunicode()
-        self.assertEqual(filter(None, "12"), "12")
-        self.assertEqual(filter(lambda x: x>="3", "1234"), "34")
-        self.assertRaises(TypeError, filter, 42, "12")
-        class badstr(str):
-            def __getitem__(self, index):
-                raise ValueError
-        self.assertRaises(ValueError, filter, lambda x: x >="3", badstr("1234"))
-
-        class badstr2(str):
-            def __getitem__(self, index):
-                return 42
-        self.assertRaises(TypeError, filter, lambda x: x >=42, badstr2("1234"))
-
-        class weirdstr(str):
-            def __getitem__(self, index):
-                return weirdstr(2*str.__getitem__(self, index))
-        self.assertEqual(filter(lambda x: x>="33", weirdstr("1234")), "3344")
-
-        class shiftstr(str):
-            def __getitem__(self, index):
-                return chr(ord(str.__getitem__(self, index))+1)
-        self.assertEqual(filter(lambda x: x>="3", shiftstr("1234")), "345")
-
-    def test_filter_subclasses(self):
-        # test that filter() never returns tuple or str subclasses
-        # and that the result always goes through __getitem__
-        funcs = (None, bool, lambda x: True)
-        class tuple2(tuple):
-            def __getitem__(self, index):
-                return 2*tuple.__getitem__(self, index)
-        class str2(str):
-            def __getitem__(self, index):
-                return 2*str.__getitem__(self, index)
-        inputs = {
-            tuple2: {(): (), (1, 2, 3): (2, 4, 6)},
-            str2:   {"": "", "123": "112233"}
-        }
-
-        for (cls, inps) in inputs.items():
-            for (inp, exp) in inps.items():
-                # make sure the output goes through __getitem__
-                # even if func is None
-                self.assertEqual(
-                    filter(funcs[0], cls(inp)),
-                    filter(funcs[1], cls(inp))
-                )
-                for func in funcs:
-                    outp = filter(func, cls(inp))
-                    self.assertEqual(outp, exp)
-                    self.assert_(not isinstance(outp, cls))
+        self.assertEqual(list(filter(None, (1, 2))), [1, 2])
+        self.assertEqual(list(filter(lambda x: x>=3, (1, 2, 3, 4))), [3, 4])
+        self.assertRaises(TypeError, list, filter(42, (1, 2)))
 
     def test_float(self):
         self.assertEqual(float(3.14), 3.14)
@@ -1102,19 +1050,19 @@ class BuiltinTest(unittest.TestCase):
 
     def test_map(self):
         self.assertEqual(
-            map(None, 'hello world'),
-            ['h','e','l','l','o',' ','w','o','r','l','d']
+            list(map(None, 'hello')),
+            [('h',), ('e',), ('l',), ('l',), ('o',)]
         )
         self.assertEqual(
-            map(None, 'abcd', 'efg'),
-            [('a', 'e'), ('b', 'f'), ('c', 'g'), ('d', None)]
+            list(map(None, 'abcd', 'efg')),
+            [('a', 'e'), ('b', 'f'), ('c', 'g')]
         )
         self.assertEqual(
-            map(None, range(10)),
-            [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+            list(map(None, range(3))),
+            [(0,), (1,), (2,)]
         )
         self.assertEqual(
-            map(lambda x: x*x, range(1,4)),
+            list(map(lambda x: x*x, range(1,4))),
             [1, 4, 9]
         )
         try:
@@ -1123,11 +1071,11 @@ class BuiltinTest(unittest.TestCase):
             def sqrt(x):
                 return pow(x, 0.5)
         self.assertEqual(
-            map(lambda x: map(sqrt,x), [[16, 4], [81, 9]]),
+            list(map(lambda x: list(map(sqrt, x)), [[16, 4], [81, 9]])),
             [[4.0, 2.0], [9.0, 3.0]]
         )
         self.assertEqual(
-            map(lambda x, y: x+y, [1,3,2], [9,1,4]),
+            list(map(lambda x, y: x+y, [1,3,2], [9,1,4])),
             [10, 4, 6]
         )
 
@@ -1136,28 +1084,28 @@ class BuiltinTest(unittest.TestCase):
             for i in v: accu = accu + i
             return accu
         self.assertEqual(
-            map(plus, [1, 3, 7]),
+            list(map(plus, [1, 3, 7])),
             [1, 3, 7]
         )
         self.assertEqual(
-            map(plus, [1, 3, 7], [4, 9, 2]),
+            list(map(plus, [1, 3, 7], [4, 9, 2])),
             [1+4, 3+9, 7+2]
         )
         self.assertEqual(
-            map(plus, [1, 3, 7], [4, 9, 2], [1, 1, 0]),
+            list(map(plus, [1, 3, 7], [4, 9, 2], [1, 1, 0])),
             [1+4+1, 3+9+1, 7+2+0]
         )
         self.assertEqual(
-            map(None, Squares(10)),
-            [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]
+            list(map(None, Squares(10))),
+            [(0,), (1,), (4,), (9,), (16,), (25,), (36,), (49,), (64,), (81,)]
         )
         self.assertEqual(
-            map(int, Squares(10)),
+            list(map(int, Squares(10))),
             [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]
         )
         self.assertEqual(
-            map(None, Squares(3), Squares(2)),
-            [(0,0), (1,1), (4,None)]
+            list(map(None, Squares(3), Squares(2))),
+            [(0,0), (1,1)]
         )
         def Max(a, b):
             if a is None:
@@ -1166,19 +1114,20 @@ class BuiltinTest(unittest.TestCase):
                 return a
             return max(a, b)
         self.assertEqual(
-            map(Max, Squares(3), Squares(2)),
-            [0, 1, 4]
+            list(map(Max, Squares(3), Squares(2))),
+            [0, 1]
         )
         self.assertRaises(TypeError, map)
         self.assertRaises(TypeError, map, lambda x: x, 42)
-        self.assertEqual(map(None, [42]), [42])
+        self.assertEqual(list(map(None, [42])), [(42,)])
         class BadSeq:
-            def __getitem__(self, index):
+            def __iter__(self):
                 raise ValueError
-        self.assertRaises(ValueError, map, lambda x: x, BadSeq())
+                yield None
+        self.assertRaises(ValueError, list, map(lambda x: x, BadSeq()))
         def badfunc(x):
             raise RuntimeError
-        self.assertRaises(RuntimeError, map, badfunc, range(5))
+        self.assertRaises(RuntimeError, list, map(badfunc, range(5)))
 
     def test_max(self):
         self.assertEqual(max('123123'), '3')
diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
index 1083321705..a48cf9cbd3 100644
--- a/Lib/test/test_bytes.py
+++ b/Lib/test/test_bytes.py
@@ -158,7 +158,7 @@ class BytesTest(unittest.TestCase):
                 b = b"x"*20
                 n = f.readinto(b)
             self.assertEqual(n, len(short_sample))
-            self.assertEqual(b, sample)
+            self.assertEqual(list(b), list(sample))
             # Test writing in binary mode
             with open(tfn, "wb") as f:
                 f.write(b)
@@ -172,7 +172,7 @@ class BytesTest(unittest.TestCase):
                 pass
 
     def test_reversed(self):
-        input = map(ord, "Hello")
+        input = list(map(ord, "Hello"))
         b = bytes(input)
         output = list(reversed(b))
         input.reverse()
@@ -469,7 +469,7 @@ class BytesTest(unittest.TestCase):
         self.assertEqual(b"".join([]), bytes())
         self.assertEqual(b"".join([bytes()]), bytes())
         for part in [("abc",), ("a", "bc"), ("ab", "c"), ("a", "b", "c")]:
-            lst = map(bytes, part)
+            lst = list(map(bytes, part))
             self.assertEqual(b"".join(lst), bytes("abc"))
             self.assertEqual(b"".join(tuple(lst)), bytes("abc"))
             self.assertEqual(b"".join(iter(lst)), bytes("abc"))
diff --git a/Lib/test/test_cgi.py b/Lib/test/test_cgi.py
index 0bf18a15e4..6d5bfd6681 100644
--- a/Lib/test/test_cgi.py
+++ b/Lib/test/test_cgi.py
@@ -121,10 +121,11 @@ def norm(seq):
     return sorted(seq, key=repr)
 
 def first_elts(list):
-    return map(lambda x:x[0], list)
+    return [p[0] for p in list]
 
 def first_second_elts(list):
-    return map(lambda p:(p[0], p[1][0]), list)
+    return [(p[0], p[1][0]) for p in list]
+
 
 class CgiTests(unittest.TestCase):
 
diff --git a/Lib/test/test_datetime.py b/Lib/test/test_datetime.py
index b827658579..3a0b7af5f8 100644
--- a/Lib/test/test_datetime.py
+++ b/Lib/test/test_datetime.py
@@ -830,8 +830,7 @@ class TestDate(HarmlessMixedComparison, unittest.TestCase):
             320  348  376
             325  353  381
         """
-        iso_long_years = map(int, ISO_LONG_YEARS_TABLE.split())
-        iso_long_years.sort()
+        iso_long_years = sorted(map(int, ISO_LONG_YEARS_TABLE.split()))
         L = []
         for i in range(400):
             d = self.theclass(2000+i, 12, 31)
diff --git a/Lib/test/test_decimal.py b/Lib/test/test_decimal.py
index 641f51c3c3..f515405da9 100644
--- a/Lib/test/test_decimal.py
+++ b/Lib/test/test_decimal.py
@@ -39,7 +39,7 @@ except ImportError:
     threading = None
 
 # Useful Test Constant
-Signals = getcontext().flags.keys()
+Signals = tuple(getcontext().flags.keys())
 
 # Tests are built around these assumed context defaults.
 # test_main() restores the original context.
@@ -171,7 +171,7 @@ class DecimalTest(unittest.TestCase):
             return self.eval_equation(s)
 
     def eval_directive(self, s):
-        funct, value = map(lambda x: x.strip().lower(), s.split(':'))
+        funct, value = (x.strip().lower() for x in s.split(':'))
         if funct == 'rounding':
             value = RoundingDict[value]
         else:
@@ -842,7 +842,7 @@ class DecimalUsabilityTest(unittest.TestCase):
         self.assertNotEqual(da, object)
 
         # sortable
-        a = map(Decimal, range(100))
+        a = list(map(Decimal, range(100)))
         b =  a[:]
         random.shuffle(a)
         a.sort()
diff --git a/Lib/test/test_extcall.py b/Lib/test/test_extcall.py
index b183189fcf..40ebad0bcf 100644
--- a/Lib/test/test_extcall.py
+++ b/Lib/test/test_extcall.py
@@ -263,8 +263,7 @@ for args in ['', 'a', 'ab']:
         for vararg in ['', 'v']:
             for kwarg in ['', 'k']:
                 name = 'z' + args + defargs + vararg + kwarg
-                arglist = list(args) + map(
-                    lambda x: '%s="%s"' % (x, x), defargs)
+                arglist = list(args) + ['%s="%s"' % (x, x) for x in defargs]
                 if vararg: arglist.append('*' + vararg)
                 if kwarg: arglist.append('**' + kwarg)
                 decl = (('def %s(%s): print("ok %s", a, b, d, e, v, ' +
diff --git a/Lib/test/test_functools.py b/Lib/test/test_functools.py
index 55c549f6ab..a1e5d13af3 100644
--- a/Lib/test/test_functools.py
+++ b/Lib/test/test_functools.py
@@ -19,6 +19,7 @@ def capture(*args, **kw):
     """capture all positional and keyword arguments"""
     return args, kw
 
+
 class TestPartial(unittest.TestCase):
 
     thetype = functools.partial
@@ -28,7 +29,7 @@ class TestPartial(unittest.TestCase):
         self.assertEqual(p(3, 4, b=30, c=40),
                          ((1, 2, 3, 4), dict(a=10, b=30, c=40)))
         p = self.thetype(map, lambda x: x*10)
-        self.assertEqual(p([1,2,3,4]), [10, 20, 30, 40])
+        self.assertEqual(list(p([1,2,3,4])), [10, 20, 30, 40])
 
     def test_attributes(self):
         p = self.thetype(capture, 1, 2, a=10, b=20)
@@ -134,7 +135,7 @@ class TestPartial(unittest.TestCase):
         self.assertRaises(ReferenceError, getattr, p, 'func')
 
     def test_with_bound_and_unbound_methods(self):
-        data = map(str, range(10))
+        data = list(map(str, range(10)))
         join = self.thetype(str.join, '')
         self.assertEqual(join(data), '0123456789')
         join = self.thetype(''.join)
diff --git a/Lib/test/test_genexps.py b/Lib/test/test_genexps.py
index 7b5fdc451e..ee582e3052 100644
--- a/Lib/test/test_genexps.py
+++ b/Lib/test/test_genexps.py
@@ -128,7 +128,7 @@ Verify late binding for the innermost for-expression
 
 Verify re-use of tuples (a side benefit of using genexps over listcomps)
 
-    >>> tupleids = map(id, ((i,i) for i in range(10)))
+    >>> tupleids = list(map(id, ((i,i) for i in range(10))))
     >>> int(max(tupleids) - min(tupleids))
     0
 
diff --git a/Lib/test/test_grp.py b/Lib/test/test_grp.py
index ede9c72821..978dee98cb 100755
--- a/Lib/test/test_grp.py
+++ b/Lib/test/test_grp.py
@@ -54,7 +54,7 @@ class GroupDatabaseTestCase(unittest.TestCase):
         namei = 0
         fakename = allnames[namei]
         while fakename in bynames:
-            chars = map(None, fakename)
+            chars = list(fakename)
             for i in range(len(chars)):
                 if chars[i] == 'z':
                     chars[i] = 'A'
@@ -71,7 +71,7 @@ class GroupDatabaseTestCase(unittest.TestCase):
                 except IndexError:
                     # should never happen... if so, just forget it
                     break
-            fakename = ''.join(map(None, chars))
+            fakename = ''.join(chars)
 
         self.assertRaises(KeyError, grp.getgrnam, fakename)
 
diff --git a/Lib/test/test_hash.py b/Lib/test/test_hash.py
index 9578537be9..eff0c7c5e5 100644
--- a/Lib/test/test_hash.py
+++ b/Lib/test/test_hash.py
@@ -11,7 +11,7 @@ class HashEqualityTestCase(unittest.TestCase):
     def same_hash(self, *objlist):
         # Hash each object given and fail if
         # the hash values are not all the same.
-        hashed = map(hash, objlist)
+        hashed = list(map(hash, objlist))
         for h in hashed[1:]:
             if h != hashed[0]:
                 self.fail("hashed values differ: %r" % (objlist,))
diff --git a/Lib/test/test_heapq.py b/Lib/test/test_heapq.py
index ceaf3cc0ee..62f9662ee6 100644
--- a/Lib/test/test_heapq.py
+++ b/Lib/test/test_heapq.py
@@ -130,16 +130,17 @@ class TestHeap(unittest.TestCase):
         data = [(random.randrange(2000), i) for i in range(1000)]
         for f in (None, lambda x:  x[0] * 547 % 2000):
             for n in (0, 1, 2, 10, 100, 400, 999, 1000, 1100):
-                self.assertEqual(nsmallest(n, data), sorted(data)[:n])
-                self.assertEqual(nsmallest(n, data, key=f),
+                self.assertEqual(list(nsmallest(n, data)), sorted(data)[:n])
+                self.assertEqual(list(nsmallest(n, data, key=f)),
                                  sorted(data, key=f)[:n])
 
     def test_nlargest(self):
         data = [(random.randrange(2000), i) for i in range(1000)]
         for f in (None, lambda x:  x[0] * 547 % 2000):
             for n in (0, 1, 2, 10, 100, 400, 999, 1000, 1100):
-                self.assertEqual(nlargest(n, data), sorted(data, reverse=True)[:n])
-                self.assertEqual(nlargest(n, data, key=f),
+                self.assertEqual(list(nlargest(n, data)),
+                                 sorted(data, reverse=True)[:n])
+                self.assertEqual(list(nlargest(n, data, key=f)),
                                  sorted(data, key=f, reverse=True)[:n])
 
 
@@ -279,8 +280,8 @@ class TestErrorHandling(unittest.TestCase):
         for f in  (nlargest, nsmallest):
             for s in ("123", "", range(1000), (1, 1.2), range(2000,2200,5)):
                 for g in (G, I, Ig, L, R):
-                    self.assertEqual(f(2, g(s)), f(2,s))
-                self.assertEqual(f(2, S(s)), [])
+                    self.assertEqual(list(f(2, g(s))), list(f(2,s)))
+                self.assertEqual(list(f(2, S(s))), [])
                 self.assertRaises(TypeError, f, 2, X(s))
                 self.assertRaises(TypeError, f, 2, N(s))
                 self.assertRaises(ZeroDivisionError, f, 2, E(s))
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
index bdd7c34eb0..75bd4087e5 100644
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -44,7 +44,7 @@ class IsTestBase(unittest.TestCase):
 
 class TestPredicates(IsTestBase):
     def test_thirteen(self):
-        count = len(filter(lambda x:x.startswith('is'), dir(inspect)))
+        count = len([x for x in dir(inspect) if x.startswith('is')])
         # Doc/lib/libinspect.tex claims there are 13 such functions
         expected = 13
         err_msg = "There are %d (not %d) is* functions" % (count, expected)
diff --git a/Lib/test/test_iter.py b/Lib/test/test_iter.py
index f7712db7b7..b92c50aad7 100644
--- a/Lib/test/test_iter.py
+++ b/Lib/test/test_iter.py
@@ -305,13 +305,14 @@ class TestCase(unittest.TestCase):
 
     # Test filter()'s use of iterators.
     def test_builtin_filter(self):
-        self.assertEqual(filter(None, SequenceClass(5)), list(range(1, 5)))
-        self.assertEqual(filter(None, SequenceClass(0)), [])
-        self.assertEqual(filter(None, ()), ())
-        self.assertEqual(filter(None, "abc"), "abc")
+        self.assertEqual(list(filter(None, SequenceClass(5))),
+                         list(range(1, 5)))
+        self.assertEqual(list(filter(None, SequenceClass(0))), [])
+        self.assertEqual(list(filter(None, ())), [])
+        self.assertEqual(list(filter(None, "abc")), ["a", "b", "c"])
 
         d = {"one": 1, "two": 2, "three": 3}
-        self.assertEqual(filter(None, d), list(d.keys()))
+        self.assertEqual(list(filter(None, d)), list(d.keys()))
 
         self.assertRaises(TypeError, filter, None, list)
         self.assertRaises(TypeError, filter, None, 42)
@@ -344,8 +345,8 @@ class TestCase(unittest.TestCase):
                 return SeqIter(self.vals)
 
         seq = Seq(*([bTrue, bFalse] * 25))
-        self.assertEqual(filter(lambda x: not x, seq), [bFalse]*25)
-        self.assertEqual(filter(lambda x: not x, iter(seq)), [bFalse]*25)
+        self.assertEqual(list(filter(lambda x: not x, seq)), [bFalse]*25)
+        self.assertEqual(list(filter(lambda x: not x, iter(seq))), [bFalse]*25)
 
     # Test max() and min()'s use of iterators.
     def test_builtin_max_min(self):
@@ -381,20 +382,24 @@ class TestCase(unittest.TestCase):
 
     # Test map()'s use of iterators.
     def test_builtin_map(self):
-        self.assertEqual(map(None, SequenceClass(5)), list(range(5)))
-        self.assertEqual(map(lambda x: x+1, SequenceClass(5)), list(range(1, 6)))
+        self.assertEqual(list(map(None, SequenceClass(5))),
+                         [(0,), (1,), (2,), (3,), (4,)])
+        self.assertEqual(list(map(lambda x: x+1, SequenceClass(5))),
+                         list(range(1, 6)))
 
         d = {"one": 1, "two": 2, "three": 3}
-        self.assertEqual(map(None, d), list(d.keys()))
-        self.assertEqual(map(lambda k, d=d: (k, d[k]), d), list(d.items()))
+        self.assertEqual(list(map(None, d)), [(k,) for k in d])
+        self.assertEqual(list(map(lambda k, d=d: (k, d[k]), d)),
+                         list(d.items()))
         dkeys = list(d.keys())
         expected = [(i < len(d) and dkeys[i] or None,
                      i,
                      i < len(d) and dkeys[i] or None)
-                    for i in range(5)]
-        self.assertEqual(map(None, d,
-                                   SequenceClass(5),
-                                   iter(d.keys())),
+                    for i in range(3)]
+        self.assertEqual(list(map(None,
+                                  d,
+                                  SequenceClass(5),
+                                  iter(d.keys()))),
                          expected)
 
         f = open(TESTFN, "w")
@@ -405,7 +410,7 @@ class TestCase(unittest.TestCase):
             f.close()
         f = open(TESTFN, "r")
         try:
-            self.assertEqual(map(len, f), list(range(1, 21, 2)))
+            self.assertEqual(list(map(len, f)), list(range(1, 21, 2)))
         finally:
             f.close()
             try:
diff --git a/Lib/test/test_itertools.py b/Lib/test/test_itertools.py
index 6dfc52e11b..e3728d8d33 100644
--- a/Lib/test/test_itertools.py
+++ b/Lib/test/test_itertools.py
@@ -199,9 +199,9 @@ class TestBasicOps(unittest.TestCase):
                          lzip('abc', 'def'))
         self.assertEqual([pair for pair in izip('abc', 'def')],
                          lzip('abc', 'def'))
-        ids = map(id, izip('abc', 'def'))
+        ids = list(map(id, izip('abc', 'def')))
         self.assertEqual(min(ids), max(ids))
-        ids = map(id, list(izip('abc', 'def')))
+        ids = list(map(id, list(izip('abc', 'def'))))
         self.assertEqual(len(dict.fromkeys(ids)), len(ids))
 
     def test_iziplongest(self):
@@ -212,7 +212,8 @@ class TestBasicOps(unittest.TestCase):
                 [range(1000), range(0), range(3000,3050), range(1200), range(1500)],
                 [range(1000), range(0), range(3000,3050), range(1200), range(1500), range(0)],
             ]:
-            target = map(None, *args)
+            target = [tuple([arg[i] if i < len(arg) else None for arg in args])
+                      for i in range(max(map(len, args)))]
             self.assertEqual(list(izip_longest(*args)), target)
             self.assertEqual(list(izip_longest(*args, **{})), target)
             target = [tuple((e is None and 'X' or e) for e in t) for t in target]   # Replace None fills with 'X'
@@ -224,7 +225,8 @@ class TestBasicOps(unittest.TestCase):
         self.assertEqual(list(izip_longest([])), list(zip([])))
         self.assertEqual(list(izip_longest('abcdef')), list(zip('abcdef')))
 
-        self.assertEqual(list(izip_longest('abc', 'defg', **{})), map(None, 'abc', 'defg')) # empty keyword dict
+        self.assertEqual(list(izip_longest('abc', 'defg', **{})),
+                         list(map(None, list('abc')+[None], 'defg'))) # empty keyword dict
         self.assertRaises(TypeError, izip_longest, 3)
         self.assertRaises(TypeError, izip_longest, range(3), 3)
 
@@ -244,9 +246,9 @@ class TestBasicOps(unittest.TestCase):
                          list(zip('abc', 'def')))
         self.assertEqual([pair for pair in izip_longest('abc', 'def')],
                          list(zip('abc', 'def')))
-        ids = map(id, izip_longest('abc', 'def'))
+        ids = list(map(id, izip_longest('abc', 'def')))
         self.assertEqual(min(ids), max(ids))
-        ids = map(id, list(izip_longest('abc', 'def')))
+        ids = list(map(id, list(izip_longest('abc', 'def'))))
         self.assertEqual(len(dict.fromkeys(ids)), len(ids))
 
     def test_repeat(self):
@@ -432,7 +434,7 @@ class TestBasicOps(unittest.TestCase):
             result = tee('abc', n)
             self.assertEqual(type(result), tuple)
             self.assertEqual(len(result), n)
-            self.assertEqual(map(list, result), [list('abc')]*n)
+            self.assertEqual([list(x) for x in result], [list('abc')]*n)
 
         # tee pass-through to copyable iterator
         a, b = tee('abc')
@@ -642,7 +644,8 @@ class TestVariousIteratorArgs(unittest.TestCase):
     def test_ifilter(self):
         for s in (range(10), range(0), range(1000), (7,11), range(2000,2200,5)):
             for g in (G, I, Ig, S, L, R):
-                self.assertEqual(list(ifilter(isEven, g(s))), filter(isEven, g(s)))
+                self.assertEqual(list(ifilter(isEven, g(s))),
+                                 [x for x in g(s) if isEven(x)])
             self.assertRaises(TypeError, ifilter, isEven, X(s))
             self.assertRaises(TypeError, ifilter, isEven, N(s))
             self.assertRaises(ZeroDivisionError, list, ifilter(isEven, E(s)))
@@ -650,7 +653,8 @@ class TestVariousIteratorArgs(unittest.TestCase):
     def test_ifilterfalse(self):
         for s in (range(10), range(0), range(1000), (7,11), range(2000,2200,5)):
             for g in (G, I, Ig, S, L, R):
-                self.assertEqual(list(ifilterfalse(isEven, g(s))), filter(isOdd, g(s)))
+                self.assertEqual(list(ifilterfalse(isEven, g(s))),
+                                 [x for x in g(s) if isOdd(x)])
             self.assertRaises(TypeError, ifilterfalse, isEven, X(s))
             self.assertRaises(TypeError, ifilterfalse, isEven, N(s))
             self.assertRaises(ZeroDivisionError, list, ifilterfalse(isEven, E(s)))
@@ -676,8 +680,10 @@ class TestVariousIteratorArgs(unittest.TestCase):
     def test_imap(self):
         for s in (range(10), range(0), range(100), (7,11), range(20,50,5)):
             for g in (G, I, Ig, S, L, R):
-                self.assertEqual(list(imap(onearg, g(s))), map(onearg, g(s)))
-                self.assertEqual(list(imap(operator.pow, g(s), g(s))), map(operator.pow, g(s), g(s)))
+                self.assertEqual(list(imap(onearg, g(s))),
+                                 [onearg(x) for x in g(s)])
+                self.assertEqual(list(imap(operator.pow, g(s), g(s))),
+                                 [x**x for x in g(s)])
             self.assertRaises(TypeError, imap, onearg, X(s))
             self.assertRaises(TypeError, imap, onearg, N(s))
             self.assertRaises(ZeroDivisionError, list, imap(onearg, E(s)))
@@ -694,7 +700,8 @@ class TestVariousIteratorArgs(unittest.TestCase):
         for s in (range(10), range(0), range(100), (7,11), range(20,50,5)):
             for g in (G, I, Ig, S, L, R):
                 ss = lzip(s, s)
-                self.assertEqual(list(starmap(operator.pow, g(ss))), map(operator.pow, g(s), g(s)))
+                self.assertEqual(list(starmap(operator.pow, g(ss))),
+                                 [x**x for x in g(s)])
             self.assertRaises(TypeError, starmap, operator.pow, X(ss))
             self.assertRaises(TypeError, starmap, operator.pow, N(ss))
             self.assertRaises(ZeroDivisionError, list, starmap(operator.pow, E(ss)))
@@ -849,7 +856,7 @@ Samuele
 >>> d = dict(a=1, b=2, c=1, d=2, e=1, f=2, g=3)
 >>> di = sorted(sorted(d.items()), key=itemgetter(1))
 >>> for k, g in groupby(di, itemgetter(1)):
-...     print(k, map(itemgetter(0), g))
+...     print(k, list(map(itemgetter(0), g)))
 ...
 1 ['a', 'c', 'e']
 2 ['b', 'd', 'f']
@@ -860,7 +867,7 @@ Samuele
 # same group.
 >>> data = [ 1,  4,5,6, 10, 15,16,17,18, 22, 25,26,27,28]
 >>> for k, g in groupby(enumerate(data), lambda t:t[0]-t[1]):
-...     print(map(operator.itemgetter(1), g))
+...     print(list(map(operator.itemgetter(1), g)))
 ...
 [1]
 [4, 5, 6]
diff --git a/Lib/test/test_long.py b/Lib/test/test_long.py
index 9e56d31c8c..140a2b04b1 100644
--- a/Lib/test/test_long.py
+++ b/Lib/test/test_long.py
@@ -23,9 +23,7 @@ KARATSUBA_CUTOFF = 70   # from longobject.c
 MAXDIGITS = 15
 
 # build some special values
-special = map(int, [0, 1, 2, BASE, BASE >> 1])
-special.append(0x5555555555555555)
-special.append(0xaaaaaaaaaaaaaaaa)
+special = [0, 1, 2, BASE, BASE >> 1, 0x5555555555555555, 0xaaaaaaaaaaaaaaaa]
 #  some solid strings of one bits
 p2 = 4  # 0 and 1 already added
 for i in range(2*SHIFT):
@@ -33,8 +31,7 @@ for i in range(2*SHIFT):
     p2 = p2 << 1
 del p2
 # add complements & negations
-special = special + map(lambda x: ~x, special) + \
-                    map(lambda x: -x, special)
+special += [~x for x in special] + [-x for x in special]
 
 
 class LongTest(unittest.TestCase):
diff --git a/Lib/test/test_mailbox.py b/Lib/test/test_mailbox.py
index 84a9e5cdc5..e426117cc1 100644
--- a/Lib/test/test_mailbox.py
+++ b/Lib/test/test_mailbox.py
@@ -1669,7 +1669,7 @@ class MaildirTestCase(unittest.TestCase):
         self._msgfiles = []
 
     def tearDown(self):
-        map(os.unlink, self._msgfiles)
+        list(map(os.unlink, self._msgfiles))
         os.rmdir(os.path.join(self._dir, "cur"))
         os.rmdir(os.path.join(self._dir, "tmp"))
         os.rmdir(os.path.join(self._dir, "new"))
diff --git a/Lib/test/test_mhlib.py b/Lib/test/test_mhlib.py
index f425cb9c0b..1b1af6a09c 100644
--- a/Lib/test/test_mhlib.py
+++ b/Lib/test/test_mhlib.py
@@ -179,18 +179,17 @@ class MhlibTests(unittest.TestCase):
 
         folders = mh.listallfolders()
         folders.sort()
-        tfolders = map(normF, ['deep', 'deep/f1', 'deep/f2', 'deep/f2/f3',
-                                'inbox', 'wide'])
-        tfolders.sort()
+        tfolders = sorted(map(normF, ['deep', 'deep/f1', 'deep/f2',
+                                      'deep/f2/f3', 'inbox', 'wide']))
         eq(folders, tfolders)
 
         folders = mh.listsubfolders('deep')
         folders.sort()
-        eq(folders, map(normF, ['deep/f1', 'deep/f2']))
+        eq(folders, list(map(normF, ['deep/f1', 'deep/f2'])))
 
         folders = mh.listallsubfolders('deep')
         folders.sort()
-        eq(folders, map(normF, ['deep/f1', 'deep/f2', 'deep/f2/f3']))
+        eq(folders, list(map(normF, ['deep/f1', 'deep/f2', 'deep/f2/f3'])))
         eq(mh.listsubfolders(normF('deep/f2')), [normF('deep/f2/f3')])
 
         eq(mh.listsubfolders('inbox'), [])
diff --git a/Lib/test/test_old_mailbox.py b/Lib/test/test_old_mailbox.py
index 7bd555758a..b8815062f4 100644
--- a/Lib/test/test_old_mailbox.py
+++ b/Lib/test/test_old_mailbox.py
@@ -35,7 +35,7 @@ class MaildirTestCase(unittest.TestCase):
         self._msgfiles = []
 
     def tearDown(self):
-        map(os.unlink, self._msgfiles)
+        list(map(os.unlink, self._msgfiles))
         os.rmdir(os.path.join(self._dir, "cur"))
         os.rmdir(os.path.join(self._dir, "tmp"))
         os.rmdir(os.path.join(self._dir, "new"))
diff --git a/Lib/test/test_operator.py b/Lib/test/test_operator.py
index 8b705e4b3a..6142a7ffb2 100644
--- a/Lib/test/test_operator.py
+++ b/Lib/test/test_operator.py
@@ -393,12 +393,12 @@ class OperatorTestCase(unittest.TestCase):
         # example used in the docs
         inventory = [('apple', 3), ('banana', 2), ('pear', 5), ('orange', 1)]
         getcount = operator.itemgetter(1)
-        self.assertEqual(map(getcount, inventory), [3, 2, 5, 1])
+        self.assertEqual(list(map(getcount, inventory)), [3, 2, 5, 1])
         self.assertEqual(sorted(inventory, key=getcount),
             [('orange', 1), ('banana', 2), ('apple', 3), ('pear', 5)])
 
         # multiple gets
-        data = map(str, range(20))
+        data = list(map(str, range(20)))
         self.assertEqual(operator.itemgetter(2,10,5)(data), ('2', '10', '5'))
         self.assertRaises(TypeError, operator.itemgetter(2, 'x', 5), data)
 
diff --git a/Lib/test/test_pwd.py b/Lib/test/test_pwd.py
index a50ed2168e..7abf905af6 100644
--- a/Lib/test/test_pwd.py
+++ b/Lib/test/test_pwd.py
@@ -59,7 +59,7 @@ class PwdTest(unittest.TestCase):
         namei = 0
         fakename = allnames[namei]
         while fakename in bynames:
-            chars = map(None, fakename)
+            chars = list(fakename)
             for i in range(len(chars)):
                 if chars[i] == 'z':
                     chars[i] = 'A'
@@ -76,7 +76,7 @@ class PwdTest(unittest.TestCase):
                 except IndexError:
                     # should never happen... if so, just forget it
                     break
-            fakename = ''.join(map(None, chars))
+            fakename = ''.join(chars)
 
         self.assertRaises(KeyError, pwd.getpwnam, fakename)
 
diff --git a/Lib/test/test_weakref.py b/Lib/test/test_weakref.py
index 92d80318b3..1399ade653 100644
--- a/Lib/test/test_weakref.py
+++ b/Lib/test/test_weakref.py
@@ -740,15 +740,15 @@ class MappingTestCase(TestBase):
         items2 = dict.copy().items()
         items1.sort()
         items2.sort()
-        self.assert_(items1 == items2,
+        self.assertEqual(items1, items2,
                      "cloning of weak-valued dictionary did not work!")
         del items1, items2
-        self.assert_(len(dict) == self.COUNT)
+        self.assertEqual(len(dict), self.COUNT)
         del objects[0]
-        self.assert_(len(dict) == (self.COUNT - 1),
+        self.assertEqual(len(dict), self.COUNT - 1,
                      "deleting object did not cause dictionary update")
         del objects, o
-        self.assert_(len(dict) == 0,
+        self.assertEqual(len(dict), 0,
                      "deleting the values did not clear the dictionary")
         # regression on SF bug #447152:
         dict = weakref.WeakValueDictionary()
@@ -875,14 +875,14 @@ class MappingTestCase(TestBase):
 
     def make_weak_keyed_dict(self):
         dict = weakref.WeakKeyDictionary()
-        objects = map(Object, range(self.COUNT))
+        objects = list(map(Object, range(self.COUNT)))
         for o in objects:
             dict[o] = o.arg
         return dict, objects
 
     def make_weak_valued_dict(self):
         dict = weakref.WeakValueDictionary()
-        objects = map(Object, range(self.COUNT))
+        objects = list(map(Object, range(self.COUNT)))
         for o in objects:
             dict[o.arg] = o
         return dict, objects
diff --git a/Lib/test/test_xml_etree.py b/Lib/test/test_xml_etree.py
index 4e21fd9973..1c5edd0d66 100644
--- a/Lib/test/test_xml_etree.py
+++ b/Lib/test/test_xml_etree.py
@@ -53,7 +53,7 @@ def summarize(elem):
     return elem.tag
 
 def summarize_list(seq):
-    return map(summarize, seq)
+    return list(map(summarize, seq))
 
 def interface():
     """
diff --git a/Lib/test/test_xml_etree_c.py b/Lib/test/test_xml_etree_c.py
index 1479247c92..49cdfdee14 100644
--- a/Lib/test/test_xml_etree_c.py
+++ b/Lib/test/test_xml_etree_c.py
@@ -51,7 +51,7 @@ def summarize(elem):
     return elem.tag
 
 def summarize_list(seq):
-    return map(summarize, seq)
+    return list(map(summarize, seq))
 
 def interface():
     """
diff --git a/Lib/textwrap.py b/Lib/textwrap.py
index 22a625250d..3afc269241 100644
--- a/Lib/textwrap.py
+++ b/Lib/textwrap.py
@@ -63,8 +63,8 @@ class TextWrapper:
 
     unicode_whitespace_trans = {}
     uspace = ord(' ')
-    for x in map(ord, _whitespace):
-        unicode_whitespace_trans[x] = uspace
+    for x in _whitespace:
+        unicode_whitespace_trans[ord(x)] = uspace
 
     # This funky little regex is just the trick for splitting
     # text up into word-wrappable chunks.  E.g.
@@ -136,7 +136,7 @@ class TextWrapper:
           'use', ' ', 'the', ' ', '-b', ' ', 'option!'
         """
         chunks = self.wordsep_re.split(text)
-        chunks = filter(None, chunks)  # remove empty chunks
+        chunks = [c for c in chunks if c]
         return chunks
 
     def _fix_sentence_endings(self, chunks):
diff --git a/Lib/unittest.py b/Lib/unittest.py
index a4ced3dd4e..16f062b3ab 100644
--- a/Lib/unittest.py
+++ b/Lib/unittest.py
@@ -586,7 +586,7 @@ class TestLoader:
         """
         def isTestMethod(attrname, testCaseClass=testCaseClass, prefix=self.testMethodPrefix):
             return attrname.startswith(prefix) and hasattr(getattr(testCaseClass, attrname), '__call__')
-        testFnNames = filter(isTestMethod, dir(testCaseClass))
+        testFnNames = list(filter(isTestMethod, dir(testCaseClass)))
         if self.sortTestMethodsUsing:
             testFnNames.sort(self.sortTestMethodsUsing)
         return testFnNames
@@ -725,7 +725,7 @@ class TextTestRunner:
         self.stream.writeln()
         if not result.wasSuccessful():
             self.stream.write("FAILED (")
-            failed, errored = map(len, (result.failures, result.errors))
+            failed, errored = len(result.failures), len(result.errors)
             if failed:
                 self.stream.write("failures=%d" % failed)
             if errored:
diff --git a/Lib/urllib2.py b/Lib/urllib2.py
index 4ae7df4bdf..f15da217cc 100644
--- a/Lib/urllib2.py
+++ b/Lib/urllib2.py
@@ -1222,7 +1222,7 @@ class FileHandler(BaseHandler):
             if host:
                 host, port = splitport(host)
             if not host or \
-                (not port and socket.gethostbyname(host) in self.get_names()):
+                (not port and _safe_gethostbyname(host) in self.get_names()):
                 return addinfourl(open(localfile, 'rb'),
                                   headers, 'file:'+file)
         except OSError as msg:
@@ -1230,6 +1230,12 @@ class FileHandler(BaseHandler):
             raise URLError(msg)
         raise URLError('file not on local host')
 
+def _safe_gethostbyname(host):
+    try:
+        return socket.gethostbyname(host)
+    except socket.gaierror:
+        return None
+
 class FTPHandler(BaseHandler):
     def ftp_open(self, req):
         import ftplib
@@ -1259,7 +1265,7 @@ class FTPHandler(BaseHandler):
             raise URLError(msg)
         path, attrs = splitattr(req.get_selector())
         dirs = path.split('/')
-        dirs = map(unquote, dirs)
+        dirs = list(map(unquote, dirs))
         dirs, file = dirs[:-1], dirs[-1]
         if dirs and not dirs[0]:
             dirs = dirs[1:]
diff --git a/Lib/zipfile.py b/Lib/zipfile.py
index 2fb1ea5643..4791aea5ad 100644
--- a/Lib/zipfile.py
+++ b/Lib/zipfile.py
@@ -793,7 +793,7 @@ class ZipFile:
             #  completely random, while the 12th contains the MSB of the CRC,
             #  and is used to check the correctness of the password.
             bytes = zef_file.read(12)
-            h = map(zd, bytes[0:12])
+            h = list(map(zd, bytes[0:12]))
             if h[11] != ((zinfo.CRC>>24) & 255):
                 raise RuntimeError, "Bad password for file %s" % name
 
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index a2e48b1d9c..db9ac2c4f8 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -23,11 +23,6 @@ const char *Py_FileSystemDefaultEncoding = "utf-8";
 const char *Py_FileSystemDefaultEncoding = NULL; /* use default */
 #endif
 
-/* Forward */
-static PyObject *filterstring(PyObject *, PyObject *);
-static PyObject *filterunicode(PyObject *, PyObject *);
-static PyObject *filtertuple (PyObject *, PyObject *);
-
 static PyObject *
 builtin___build_class__(PyObject *self, PyObject *args, PyObject *kwds)
 {
@@ -263,121 +258,26 @@ Return the binary representation of an integer or long integer.");
 static PyObject *
 builtin_filter(PyObject *self, PyObject *args)
 {
-	PyObject *func, *seq, *result, *it, *arg;
-	Py_ssize_t len;   /* guess for result list size */
-	register Py_ssize_t j;
-
-	if (!PyArg_UnpackTuple(args, "filter", 2, 2, &func, &seq))
+	PyObject *itertools, *ifilter, *result;
+	itertools = PyImport_ImportModule("itertools");
+	if (itertools == NULL)
 		return NULL;
-
-	/* Strings and tuples return a result of the same type. */
-	if (PyString_Check(seq))
-		return filterstring(func, seq);
-	if (PyUnicode_Check(seq))
-		return filterunicode(func, seq);
-	if (PyTuple_Check(seq))
-		return filtertuple(func, seq);
-
-	/* Pre-allocate argument list tuple. */
-	arg = PyTuple_New(1);
-	if (arg == NULL)
+	ifilter = PyObject_GetAttrString(itertools, "ifilter");
+	Py_DECREF(itertools);
+	if (ifilter == NULL)
 		return NULL;
-
-	/* Get iterator. */
-	it = PyObject_GetIter(seq);
-	if (it == NULL)
-		goto Fail_arg;
-
-	/* Guess a result list size. */
-	len = _PyObject_LengthHint(seq);
-	if (len < 0) {
-		if (!PyErr_ExceptionMatches(PyExc_TypeError)  &&
-		    !PyErr_ExceptionMatches(PyExc_AttributeError)) {
-			goto Fail_it;
-		}
-		PyErr_Clear();
-		len = 8;	/* arbitrary */
-	}
-
-	/* Get a result list. */
-	if (PyList_Check(seq) && seq->ob_refcnt == 1) {
-		/* Eww - can modify the list in-place. */
-		Py_INCREF(seq);
-		result = seq;
-	}
-	else {
-		result = PyList_New(len);
-		if (result == NULL)
-			goto Fail_it;
-	}
-
-	/* Build the result list. */
-	j = 0;
-	for (;;) {
-		PyObject *item;
-		int ok;
-
-		item = PyIter_Next(it);
-		if (item == NULL) {
-			if (PyErr_Occurred())
-				goto Fail_result_it;
-			break;
-		}
-
-		if (func == (PyObject *)&PyBool_Type || func == Py_None) {
-			ok = PyObject_IsTrue(item);
-		}
-		else {
-			PyObject *good;
-			PyTuple_SET_ITEM(arg, 0, item);
-			good = PyObject_Call(func, arg, NULL);
-			PyTuple_SET_ITEM(arg, 0, NULL);
-			if (good == NULL) {
-				Py_DECREF(item);
-				goto Fail_result_it;
-			}
-			ok = PyObject_IsTrue(good);
-			Py_DECREF(good);
-		}
-		if (ok) {
-			if (j < len)
-				PyList_SET_ITEM(result, j, item);
-			else {
-				int status = PyList_Append(result, item);
-				Py_DECREF(item);
-				if (status < 0)
-					goto Fail_result_it;
-			}
-			++j;
-		}
-		else
-			Py_DECREF(item);
-	}
-
-
-	/* Cut back result list if len is too big. */
-	if (j < len && PyList_SetSlice(result, j, len, NULL) < 0)
-		goto Fail_result_it;
-
-	Py_DECREF(it);
-	Py_DECREF(arg);
+	result = PyObject_Call(ifilter, args, NULL);
+	Py_DECREF(ifilter);
 	return result;
-
-Fail_result_it:
-	Py_DECREF(result);
-Fail_it:
-	Py_DECREF(it);
-Fail_arg:
-	Py_DECREF(arg);
-	return NULL;
 }
 
 PyDoc_STRVAR(filter_doc,
-"filter(function or None, sequence) -> list, tuple, or string\n"
-"\n"
-"Return those items of sequence for which function(item) is true.  If\n"
-"function is None, return the items that are true.  If sequence is a tuple\n"
-"or string, return the same type, else return a list.");
+"filter(predicate, iterable) -> iterator\n\
+\n\
+Return an iterator yielding only those elements of the input iterable\n\
+for which the predicate (a Boolean function) returns true.\n\
+If the predicate is None, 'lambda x: bool(x)' is assumed.\n\
+(This is identical to itertools.ifilter().)");
 
 
 static PyObject *
@@ -940,168 +840,28 @@ simultaneously existing objects.  (Hint: it's the object's memory address.)");
 static PyObject *
 builtin_map(PyObject *self, PyObject *args)
 {
-	typedef struct {
-		PyObject *it;	/* the iterator object */
-		int saw_StopIteration;  /* bool:  did the iterator end? */
-	} sequence;
-
-	PyObject *func, *result;
-	sequence *seqs = NULL, *sqp;
-	Py_ssize_t n, len;
-	register int i, j;
-
-	n = PyTuple_Size(args);
-	if (n < 2) {
-		PyErr_SetString(PyExc_TypeError,
-				"map() requires at least two args");
+	PyObject *itertools, *imap, *result;
+	itertools = PyImport_ImportModule("itertools");
+	if (itertools == NULL)
 		return NULL;
-	}
-
-	func = PyTuple_GetItem(args, 0);
-	n--;
-
-	if (func == Py_None && n == 1) {
-		/* map(None, S) is the same as list(S). */
-		return PySequence_List(PyTuple_GetItem(args, 1));
-	}
-
-	/* Get space for sequence descriptors.  Must NULL out the iterator
-	 * pointers so that jumping to Fail_2 later doesn't see trash.
-	 */
-	if ((seqs = PyMem_NEW(sequence, n)) == NULL) {
-		PyErr_NoMemory();
+	imap = PyObject_GetAttrString(itertools, "imap");
+	Py_DECREF(itertools);
+	if (imap == NULL)
 		return NULL;
-	}
-	for (i = 0; i < n; ++i) {
-		seqs[i].it = (PyObject*)NULL;
-		seqs[i].saw_StopIteration = 0;
-	}
-
-	/* Do a first pass to obtain iterators for the arguments, and set len
-	 * to the largest of their lengths.
-	 */
-	len = 0;
-	for (i = 0, sqp = seqs; i < n; ++i, ++sqp) {
-		PyObject *curseq;
-		Py_ssize_t curlen;
-
-		/* Get iterator. */
-		curseq = PyTuple_GetItem(args, i+1);
-		sqp->it = PyObject_GetIter(curseq);
-		if (sqp->it == NULL) {
-			static char errmsg[] =
-			    "argument %d to map() must support iteration";
-			char errbuf[sizeof(errmsg) + 25];
-			PyOS_snprintf(errbuf, sizeof(errbuf), errmsg, i+2);
-			PyErr_SetString(PyExc_TypeError, errbuf);
-			goto Fail_2;
-		}
-
-		/* Update len. */
-		curlen = _PyObject_LengthHint(curseq);
-		if (curlen < 0) {
-			if (!PyErr_ExceptionMatches(PyExc_TypeError)  &&
-			    !PyErr_ExceptionMatches(PyExc_AttributeError)) {
-				goto Fail_2;
-			}
-			PyErr_Clear();
-			curlen = 8;  /* arbitrary */
-		}
-		if (curlen > len)
-			len = curlen;
-	}
-
-	/* Get space for the result list. */
-	if ((result = (PyObject *) PyList_New(len)) == NULL)
-		goto Fail_2;
-
-	/* Iterate over the sequences until all have stopped. */
-	for (i = 0; ; ++i) {
-		PyObject *alist, *item=NULL, *value;
-		int numactive = 0;
-
-		if (func == Py_None && n == 1)
-			alist = NULL;
-		else if ((alist = PyTuple_New(n)) == NULL)
-			goto Fail_1;
-
-		for (j = 0, sqp = seqs; j < n; ++j, ++sqp) {
-			if (sqp->saw_StopIteration) {
-				Py_INCREF(Py_None);
-				item = Py_None;
-			}
-			else {
-				item = PyIter_Next(sqp->it);
-				if (item)
-					++numactive;
-				else {
-					if (PyErr_Occurred()) {
-						Py_XDECREF(alist);
-						goto Fail_1;
-					}
-					Py_INCREF(Py_None);
-					item = Py_None;
-					sqp->saw_StopIteration = 1;
-				}
-			}
-			if (alist)
-				PyTuple_SET_ITEM(alist, j, item);
-			else
-				break;
-		}
-
-		if (!alist)
-			alist = item;
-
-		if (numactive == 0) {
-			Py_DECREF(alist);
-			break;
-		}
-
-		if (func == Py_None)
-			value = alist;
-		else {
-			value = PyEval_CallObject(func, alist);
-			Py_DECREF(alist);
-			if (value == NULL)
-				goto Fail_1;
-		}
-		if (i >= len) {
-			int status = PyList_Append(result, value);
-			Py_DECREF(value);
-			if (status < 0)
-				goto Fail_1;
-		}
-		else if (PyList_SetItem(result, i, value) < 0)
-		 	goto Fail_1;
-	}
-
-	if (i < len && PyList_SetSlice(result, i, len, NULL) < 0)
-		goto Fail_1;
-
-	goto Succeed;
-
-Fail_1:
-	Py_DECREF(result);
-Fail_2:
-	result = NULL;
-Succeed:
-	assert(seqs);
-	for (i = 0; i < n; ++i)
-		Py_XDECREF(seqs[i].it);
-	PyMem_DEL(seqs);
+	result = PyObject_Call(imap, args, NULL);
+	Py_DECREF(imap);
 	return result;
 }
 
 PyDoc_STRVAR(map_doc,
-"map(function, sequence[, sequence, ...]) -> list\n\
+"map(function, iterable[, iterable, ...]) -> iterator\n\
 \n\
-Return a list of the results of applying the function to the items of\n\
-the argument sequence(s).  If more than one sequence is given, the\n\
-function is called with an argument list consisting of the corresponding\n\
-item of each sequence, substituting None for missing values when not all\n\
-sequences have the same length.  If the function is None, return a list of\n\
-the items of the sequence (or a list of tuples if more than one sequence).");
+Return an iterator yielding the results of applying the function to the\n\
+items of the argument iterables(s).  If more than one iterable is given,\n\
+the function is called with an argument list consisting of the\n\
+corresponding item of each iterable, until an iterable is exhausted.\n\
+If the function is None, 'lambda *a: a' is assumed.\n\
+(This is identical to itertools.imap().)");
 
 
 static PyObject *
@@ -1570,29 +1330,36 @@ builtin_input(PyObject *self, PyObject *args)
 	/* First of all, flush stderr */
 	tmp = PyObject_CallMethod(ferr, "flush", "");
 	if (tmp == NULL)
-		return NULL;
-	Py_DECREF(tmp);
+		PyErr_Clear();
+	else
+		Py_DECREF(tmp);
 
 	/* We should only use (GNU) readline if Python's sys.stdin and
 	   sys.stdout are the same as C's stdin and stdout, because we
 	   need to pass it those. */
 	tmp = PyObject_CallMethod(fin, "fileno", "");
-	if (tmp == NULL)
-		return NULL;
-	fd = PyInt_AsLong(tmp);
-	if (fd < 0 && PyErr_Occurred())
-		return NULL;
-	Py_DECREF(tmp);
-	tty = fd == fileno(stdin) && isatty(fd);
-	if (tty) {
-		tmp = PyObject_CallMethod(fout, "fileno", "");
-		if (tmp == NULL)
-			return NULL;
+	if (tmp == NULL) {
+		PyErr_Clear();
+		tty = 0;
+	}
+	else {
 		fd = PyInt_AsLong(tmp);
 		Py_DECREF(tmp);
 		if (fd < 0 && PyErr_Occurred())
 			return NULL;
-		tty = fd == fileno(stdout) && isatty(fd);
+		tty = fd == fileno(stdin) && isatty(fd);
+	}
+	if (tty) {
+		tmp = PyObject_CallMethod(fout, "fileno", "");
+		if (tmp == NULL)
+			PyErr_Clear();
+		else {
+			fd = PyInt_AsLong(tmp);
+			Py_DECREF(tmp);
+			if (fd < 0 && PyErr_Occurred())
+				return NULL;
+			tty = fd == fileno(stdout) && isatty(fd);
+		}
 	}
 
 	/* If we're interactive, use (GNU) readline */
@@ -1603,8 +1370,9 @@ builtin_input(PyObject *self, PyObject *args)
 		PyObject *result;
 		tmp = PyObject_CallMethod(fout, "flush", "");
 		if (tmp == NULL)
-			return NULL;
-		Py_DECREF(tmp);
+			PyErr_Clear();
+		else
+			Py_DECREF(tmp);
 		if (promptarg != NULL) {
 			po = PyObject_Str(promptarg);
 			if (po == NULL)
@@ -1652,8 +1420,9 @@ builtin_input(PyObject *self, PyObject *args)
 	}
 	tmp = PyObject_CallMethod(fout, "flush", "");
 	if (tmp == NULL)
-		return NULL;
-	Py_DECREF(tmp);
+		PyErr_Clear();
+	else
+		Py_DECREF(tmp);
 	return PyFile_GetLine(fin, -1);
 }
 
@@ -1921,7 +1690,7 @@ PyDoc_STRVAR(zip_doc,
 Return an iterator yielding tuples, where each tuple contains the\n\
 corresponding element from each of the argument iterables.\n\
 The returned iterator ends when the shortest argument iterable is exhausted.\n\
-NOTE: This is implemented using itertools.izip().");
+(This is identical to itertools.izip().)");
 
 
 static PyMethodDef builtin_methods[] = {
@@ -2048,262 +1817,3 @@ _PyBuiltin_Init(void)
 #undef ADD_TO_ALL
 #undef SETBUILTIN
 }
-
-/* Helper for filter(): filter a tuple through a function */
-
-static PyObject *
-filtertuple(PyObject *func, PyObject *tuple)
-{
-	PyObject *result;
-	Py_ssize_t i, j;
-	Py_ssize_t len = PyTuple_Size(tuple);
-
-	if (len == 0) {
-		if (PyTuple_CheckExact(tuple))
-			Py_INCREF(tuple);
-		else
-			tuple = PyTuple_New(0);
-		return tuple;
-	}
-
-	if ((result = PyTuple_New(len)) == NULL)
-		return NULL;
-
-	for (i = j = 0; i < len; ++i) {
-		PyObject *item, *good;
-		int ok;
-
-		if (tuple->ob_type->tp_as_sequence &&
-		    tuple->ob_type->tp_as_sequence->sq_item) {
-			item = tuple->ob_type->tp_as_sequence->sq_item(tuple, i);
-			if (item == NULL)
-				goto Fail_1;
-		} else {
-			PyErr_SetString(PyExc_TypeError, "filter(): unsubscriptable tuple");
-			goto Fail_1;
-		}
-		if (func == Py_None) {
-			Py_INCREF(item);
-			good = item;
-		}
-		else {
-			PyObject *arg = PyTuple_Pack(1, item);
-			if (arg == NULL) {
-				Py_DECREF(item);
-				goto Fail_1;
-			}
-			good = PyEval_CallObject(func, arg);
-			Py_DECREF(arg);
-			if (good == NULL) {
-				Py_DECREF(item);
-				goto Fail_1;
-			}
-		}
-		ok = PyObject_IsTrue(good);
-		Py_DECREF(good);
-		if (ok) {
-			if (PyTuple_SetItem(result, j++, item) < 0)
-				goto Fail_1;
-		}
-		else
-			Py_DECREF(item);
-	}
-
-	if (_PyTuple_Resize(&result, j) < 0)
-		return NULL;
-
-	return result;
-
-Fail_1:
-	Py_DECREF(result);
-	return NULL;
-}
-
-
-/* Helper for filter(): filter a string through a function */
-
-static PyObject *
-filterstring(PyObject *func, PyObject *strobj)
-{
-	PyObject *result;
-	Py_ssize_t i, j;
-	Py_ssize_t len = PyString_Size(strobj);
-	Py_ssize_t outlen = len;
-
-	if (func == Py_None) {
-		/* If it's a real string we can return the original,
-		 * as no character is ever false and __getitem__
-		 * does return this character. If it's a subclass
-		 * we must go through the __getitem__ loop */
-		if (PyString_CheckExact(strobj)) {
-			Py_INCREF(strobj);
-			return strobj;
-		}
-	}
-	if ((result = PyString_FromStringAndSize(NULL, len)) == NULL)
-		return NULL;
-
-	for (i = j = 0; i < len; ++i) {
-		PyObject *item;
-		int ok;
-
-		item = (*strobj->ob_type->tp_as_sequence->sq_item)(strobj, i);
-		if (item == NULL)
-			goto Fail_1;
-		if (func==Py_None) {
-			ok = 1;
-		} else {
-			PyObject *arg, *good;
-			arg = PyTuple_Pack(1, item);
-			if (arg == NULL) {
-				Py_DECREF(item);
-				goto Fail_1;
-			}
-			good = PyEval_CallObject(func, arg);
-			Py_DECREF(arg);
-			if (good == NULL) {
-				Py_DECREF(item);
-				goto Fail_1;
-			}
-			ok = PyObject_IsTrue(good);
-			Py_DECREF(good);
-		}
-		if (ok) {
-			Py_ssize_t reslen;
-			if (!PyString_Check(item)) {
-				PyErr_SetString(PyExc_TypeError, "can't filter str to str:"
-					" __getitem__ returned different type");
-				Py_DECREF(item);
-				goto Fail_1;
-			}
-			reslen = PyString_GET_SIZE(item);
-			if (reslen == 1) {
-				PyString_AS_STRING(result)[j++] =
-					PyString_AS_STRING(item)[0];
-			} else {
-				/* do we need more space? */
-				Py_ssize_t need = j + reslen + len-i-1;
-				if (need > outlen) {
-					/* overallocate, to avoid reallocations */
-					if (need<2*outlen)
-						need = 2*outlen;
-					if (_PyString_Resize(&result, need)) {
-						Py_DECREF(item);
-						return NULL;
-					}
-					outlen = need;
-				}
-				memcpy(
-					PyString_AS_STRING(result) + j,
-					PyString_AS_STRING(item),
-					reslen
-				);
-				j += reslen;
-			}
-		}
-		Py_DECREF(item);
-	}
-
-	if (j < outlen)
-		_PyString_Resize(&result, j);
-
-	return result;
-
-Fail_1:
-	Py_DECREF(result);
-	return NULL;
-}
-
-/* Helper for filter(): filter a Unicode object through a function */
-
-static PyObject *
-filterunicode(PyObject *func, PyObject *strobj)
-{
-	PyObject *result;
-	register Py_ssize_t i, j;
-	Py_ssize_t len = PyUnicode_GetSize(strobj);
-	Py_ssize_t outlen = len;
-
-	if (func == Py_None) {
-		/* If it's a real string we can return the original,
-		 * as no character is ever false and __getitem__
-		 * does return this character. If it's a subclass
-		 * we must go through the __getitem__ loop */
-		if (PyUnicode_CheckExact(strobj)) {
-			Py_INCREF(strobj);
-			return strobj;
-		}
-	}
-	if ((result = PyUnicode_FromUnicode(NULL, len)) == NULL)
-		return NULL;
-
-	for (i = j = 0; i < len; ++i) {
-		PyObject *item, *arg, *good;
-		int ok;
-
-		item = (*strobj->ob_type->tp_as_sequence->sq_item)(strobj, i);
-		if (item == NULL)
-			goto Fail_1;
-		if (func == Py_None) {
-			ok = 1;
-		} else {
-			arg = PyTuple_Pack(1, item);
-			if (arg == NULL) {
-				Py_DECREF(item);
-				goto Fail_1;
-			}
-			good = PyEval_CallObject(func, arg);
-			Py_DECREF(arg);
-			if (good == NULL) {
-				Py_DECREF(item);
-				goto Fail_1;
-			}
-			ok = PyObject_IsTrue(good);
-			Py_DECREF(good);
-		}
-		if (ok) {
-			Py_ssize_t reslen;
-			if (!PyUnicode_Check(item)) {
-				PyErr_SetString(PyExc_TypeError,
-				"can't filter unicode to unicode:"
-				" __getitem__ returned different type");
-				Py_DECREF(item);
-				goto Fail_1;
-			}
-			reslen = PyUnicode_GET_SIZE(item);
-			if (reslen == 1)
-				PyUnicode_AS_UNICODE(result)[j++] =
-					PyUnicode_AS_UNICODE(item)[0];
-			else {
-				/* do we need more space? */
-				Py_ssize_t need = j + reslen + len - i - 1;
-				if (need > outlen) {
-					/* overallocate,
-					   to avoid reallocations */
-					if (need < 2 * outlen)
-						need = 2 * outlen;
-					if (PyUnicode_Resize(
-						&result, need) < 0) {
-						Py_DECREF(item);
-						goto Fail_1;
-					}
-					outlen = need;
-				}
-				memcpy(PyUnicode_AS_UNICODE(result) + j,
-				       PyUnicode_AS_UNICODE(item),
-				       reslen*sizeof(Py_UNICODE));
-				j += reslen;
-			}
-		}
-		Py_DECREF(item);
-	}
-
-	if (j < outlen)
-		PyUnicode_Resize(&result, j);
-
-	return result;
-
-Fail_1:
-	Py_DECREF(result);
-	return NULL;
-}
diff --git a/setup.py b/setup.py
index b1e1c1e938..87673d1796 100644
--- a/setup.py
+++ b/setup.py
@@ -728,7 +728,7 @@ class PyBuildExt(build_ext):
                     db_incdir.replace("include", 'lib64'),
                     db_incdir.replace("include", 'lib'),
                 ]
-                db_dirs_to_check = filter(os.path.isdir, db_dirs_to_check)
+                db_dirs_to_check = [x for x in db_dirs_to_check if os.path.isdir(x)]
 
                 # Look for a version specific db-X.Y before an ambiguoius dbX
                 # XXX should we -ever- look for a dbX name?  Do any
@@ -1555,7 +1555,7 @@ def main():
           description = "A high-level object-oriented programming language",
           long_description = SUMMARY.strip(),
           license = "PSF license",
-          classifiers = filter(None, CLASSIFIERS.split("\n")),
+          classifiers = [x for x in CLASSIFIERS.split("\n") if x],
           platforms = ["Many"],
 
           # Build info