http://scons.tigris.org/issues/show_bug.cgi?id=2329

Applied a number of idiomatic changes.

Uses of the 'sort()' method were converted into calls of 'sorted()' when
possible and the sorted() expression was inserted into a subsequent statement
whenever that made sense.

The statement 'while 1:' was changed to 'while True:'.

Names from the 'types' module (e.g., 'types.FooType') were converted to the
equivalent build-in type (e.g., 'foo').

Comparisons between types were changed to use 'isinstance()'.

54 files changed, 179 insertions, 240 deletions

diff --git a/src/engine/SCons/Action.py b/src/engine/SCons/Action.py
index 35c7316..9d49752 100644
--- a/src/engine/SCons/Action.py
+++ b/src/engine/SCons/Action.py
@@ -704,7 +704,7 @@ class CommandAction(_ActionAction):
             result = env.subst_list(self.cmd_list, 0, target, source)
         silent = None
         ignore = None
-        while 1:
+        while True:
             try: c = result[0][0][0]
             except IndexError: c = None
             if c == '@': silent = 1
diff --git a/src/engine/SCons/ActionTests.py b/src/engine/SCons/ActionTests.py
index 12756e5..052582b 100644
--- a/src/engine/SCons/ActionTests.py
+++ b/src/engine/SCons/ActionTests.py
@@ -304,7 +304,9 @@ class ActionTestCase(unittest.TestCase):
         # a singleton list returns the contained action
         test_positional_args(cmd_action, ["string"])
 
-        if hasattr(types, 'UnicodeType'):
+        try: unicode
+        except NameError: pass
+        else:
             a2 = eval("SCons.Action.Action(u'string')")
             assert isinstance(a2, SCons.Action.CommandAction), a2
 
@@ -540,18 +542,18 @@ class _ActionActionTestCase(unittest.TestCase):
             env = Environment()
 
             def execfunc(target, source, env):
-                assert type(target) is type([]), type(target)
-                assert type(source) is type([]), type(source)
+                assert isinstance(target, list), type(target)
+                assert isinstance(source, list), type(source)
                 return 7
             a = SCons.Action.Action(execfunc)
 
             def firstfunc(target, source, env):
-                assert type(target) is type([]), type(target)
-                assert type(source) is type([]), type(source)
+                assert isinstance(target, list), type(target)
+                assert isinstance(source, list), type(source)
                 return 0
             def lastfunc(target, source, env):
-                assert type(target) is type([]), type(target)
-                assert type(source) is type([]), type(source)
+                assert isinstance(target, list), type(target)
+                assert isinstance(source, list), type(source)
                 return 9
             b = SCons.Action.Action([firstfunc, execfunc, lastfunc])
             
diff --git a/src/engine/SCons/BuilderTests.py b/src/engine/SCons/BuilderTests.py
index f26aa67..e4ddaec 100644
--- a/src/engine/SCons/BuilderTests.py
+++ b/src/engine/SCons/BuilderTests.py
@@ -35,7 +35,6 @@ def Func():
 import os.path
 import re
 import sys
-import types
 import StringIO
 import unittest
 import UserList
@@ -306,7 +305,8 @@ class BuilderTestCase(unittest.TestCase):
         #be = target.get_build_env()
         #assert be['VAR'] == 'foo', be['VAR']
 
-        if not hasattr(types, 'UnicodeType'):
+        try: unicode
+        except NameError:
             uni = str
         else:
             uni = unicode
diff --git a/src/engine/SCons/Conftest.py b/src/engine/SCons/Conftest.py
index 9221e2f..04a6bc2 100644
--- a/src/engine/SCons/Conftest.py
+++ b/src/engine/SCons/Conftest.py
@@ -729,7 +729,7 @@ def _Have(context, key, have, comment = None):
         line = "#define %s 1\n" % key_up
     elif have == 0:
         line = "/* #undef %s */\n" % key_up
-    elif type(have) == IntType:
+    elif isinstance(have, IntType):
         line = "#define %s %d\n" % (key_up, have)
     else:
         line = "#define %s %s\n" % (key_up, str(have))
diff --git a/src/engine/SCons/Debug.py b/src/engine/SCons/Debug.py
index a6c0cb5..18e6546 100644
--- a/src/engine/SCons/Debug.py
+++ b/src/engine/SCons/Debug.py
@@ -55,9 +55,7 @@ tracked_classes = {}
 
 def string_to_classes(s):
     if s == '*':
-        c = tracked_classes.keys()
-        c.sort()
-        return c
+        return sorted(tracked_classes.keys())
     else:
         return s.split()
 
@@ -148,21 +146,15 @@ def caller_trace(back=0):
 
 # print a single caller and its callers, if any
 def _dump_one_caller(key, file, level=0):
-    l = []
-    for c,v in caller_dicts[key].items():
-        l.append((-v,c))
-    l.sort()
     leader = '      '*level
-    for v,c in l:
+    for v,c in sorted([(-v,c) for c,v in caller_dicts[key].items()]):
         file.write("%s  %6d %s:%d(%s)\n" % ((leader,-v) + func_shorten(c[-3:])))
         if c in caller_dicts:
             _dump_one_caller(c, file, level+1)
 
 # print each call tree
 def dump_caller_counts(file=sys.stdout):
-    keys = caller_bases.keys()
-    keys.sort()
-    for k in keys:
+    for k in sorted(caller_bases.keys()):
         file.write("Callers of %s:%d(%s), %d calls:\n"
                     % (func_shorten(k) + (caller_bases[k],)))
         _dump_one_caller(k, file)
diff --git a/src/engine/SCons/Defaults.py b/src/engine/SCons/Defaults.py
index 2f48d0d..f532354 100644
--- a/src/engine/SCons/Defaults.py
+++ b/src/engine/SCons/Defaults.py
@@ -42,7 +42,6 @@ import errno
 import shutil
 import stat
 import time
-import types
 import sys
 
 import SCons.Action
@@ -373,7 +372,7 @@ def processDefines(defs):
     if SCons.Util.is_List(defs):
         l = []
         for d in defs:
-            if SCons.Util.is_List(d) or type(d) is types.TupleType:
+            if SCons.Util.is_List(d) or isinstance(d, tuple):
                 l.append(str(d[0]) + '=' + str(d[1]))
             else:
                 l.append(str(d))
@@ -385,10 +384,7 @@ def processDefines(defs):
         # Consequently, we have to sort the keys to ensure a
         # consistent order...
         l = []
-        keys = defs.keys()
-        keys.sort()
-        for k in keys:
-            v = defs[k]
+        for k,v in sorted(defs.items()):
             if v is None:
                 l.append(str(k))
             else:
diff --git a/src/engine/SCons/DefaultsTests.py b/src/engine/SCons/DefaultsTests.py
index 8534cf8..99cb120 100644
--- a/src/engine/SCons/DefaultsTests.py
+++ b/src/engine/SCons/DefaultsTests.py
@@ -27,7 +27,6 @@ import os
 import os.path
 import StringIO
 import sys
-import types
 import unittest
 
 from UserDict import UserDict
diff --git a/src/engine/SCons/Environment.py b/src/engine/SCons/Environment.py
index 3ebba12..267b73d 100644
--- a/src/engine/SCons/Environment.py
+++ b/src/engine/SCons/Environment.py
@@ -99,7 +99,7 @@ def apply_tools(env, tools, toolpath):
         return
     # Filter out null tools from the list.
     for tool in [_f for _f in tools if _f]:
-        if SCons.Util.is_List(tool) or type(tool)==type(()):
+        if SCons.Util.is_List(tool) or isinstance(tool, tuple):
             toolname = tool[0]
             toolargs = tool[1] # should be a dict of kw args
             tool = env.Tool(toolname, **toolargs)
diff --git a/src/engine/SCons/EnvironmentTests.py b/src/engine/SCons/EnvironmentTests.py
index b692e96..2540408 100644
--- a/src/engine/SCons/EnvironmentTests.py
+++ b/src/engine/SCons/EnvironmentTests.py
@@ -128,7 +128,7 @@ class Scanner:
 
 class CLVar(UserList.UserList):
     def __init__(self, seq):
-        if type(seq) == type(''):
+        if isinstance(seq, str):
             seq = seq.split()
         UserList.UserList.__init__(self, seq)
     def __add__(self, other):
@@ -271,8 +271,9 @@ class SubstitutionTestCase(unittest.TestCase):
         assert isinstance(nodes[0], X)
         assert nodes[0].name == "Util.py UtilTests.py"
 
-        import types
-        if hasattr(types, 'UnicodeType'):
+        try: unicode
+        except NameError: pass
+        else:
             code = """if 1:
                 nodes = env.arg2nodes(u"Util.py UtilTests.py", Factory)
                 assert len(nodes) == 1, nodes
diff --git a/src/engine/SCons/Job.py b/src/engine/SCons/Job.py
index 5d6befe..08e37a5 100644
--- a/src/engine/SCons/Job.py
+++ b/src/engine/SCons/Job.py
@@ -189,7 +189,7 @@ class Serial:
         fails to execute (i.e. execute() raises an exception), then the job will
         stop."""
         
-        while 1:
+        while True:
             task = self.taskmaster.next_task()
 
             if task is None:
@@ -242,7 +242,7 @@ else:
             self.start()
 
         def run(self):
-            while 1:
+            while True:
                 task = self.requestQueue.get()
 
                 if task is None:
@@ -376,7 +376,7 @@ else:
 
             jobs = 0
             
-            while 1:
+            while True:
                 # Start up as many available tasks as we're
                 # allowed to.
                 while jobs < self.maxjobs:
@@ -404,7 +404,7 @@ else:
 
                 # Let any/all completed tasks finish up before we go
                 # back and put the next batch of tasks on the queue.
-                while 1:
+                while True:
                     task, ok = self.tp.get()
                     jobs = jobs - 1
 
diff --git a/src/engine/SCons/JobTests.py b/src/engine/SCons/JobTests.py
index afa00fb..85708ad 100644
--- a/src/engine/SCons/JobTests.py
+++ b/src/engine/SCons/JobTests.py
@@ -527,8 +527,8 @@ if __name__ == "__main__":
     result = runner.run(suite())
     if (len(result.failures) == 0
         and len(result.errors) == 1
-        and type(result.errors[0][0]) == SerialTestCase
-        and type(result.errors[0][1][0]) == NoThreadsException):
+        and isinstance(result.errors[0][0], SerialTestCase)
+        and isinstance(result.errors[0][1][0], NoThreadsException)):
         sys.exit(2)
     elif not result.wasSuccessful():
         sys.exit(1)
diff --git a/src/engine/SCons/Node/FS.py b/src/engine/SCons/Node/FS.py
index 705e0bc..e5b8147 100644
--- a/src/engine/SCons/Node/FS.py
+++ b/src/engine/SCons/Node/FS.py
@@ -1682,10 +1682,7 @@ class Dir(Base):
         """Return content signatures and names of all our children
         separated by new-lines. Ensure that the nodes are sorted."""
         contents = []
-        name_cmp = lambda a, b: cmp(a.name, b.name)
-        sorted_children = self.children()[:]
-        sorted_children.sort(name_cmp)
-        for node in sorted_children:
+        for node in sorted(self.children(), key=lambda t: t.name):
             contents.append('%s %s\n' % (node.get_csig(), node.name))
         return ''.join(contents)
 
@@ -1952,9 +1949,8 @@ class Dir(Base):
         """
         dirname, basename = os.path.split(pathname)
         if not dirname:
-            result = self._glob1(basename, ondisk, source, strings)
-            result.sort(lambda a, b: cmp(str(a), str(b)))
-            return result
+            return sorted(self._glob1(basename, ondisk, source, strings),
+                          key=lambda t: str(t))
         if has_glob_magic(dirname):
             list = self.glob(dirname, ondisk, source, strings=False)
         else:
diff --git a/src/engine/SCons/Node/FSTests.py b/src/engine/SCons/Node/FSTests.py
index af7638d..e68b389 100644
--- a/src/engine/SCons/Node/FSTests.py
+++ b/src/engine/SCons/Node/FSTests.py
@@ -1722,8 +1722,7 @@ class DirTestCase(_tempdirTestCase):
         fs.Dir(os.path.join('ddd', 'd1', 'f4'))
         fs.Dir(os.path.join('ddd', 'd1', 'f5'))
         dir.scan()
-        kids = [x.path for x in dir.children(None)]
-        kids.sort()
+        kids = sorted([x.path for x in dir.children(None)])
         assert kids == [os.path.join('ddd', 'd1'),
                         os.path.join('ddd', 'f1'),
                         os.path.join('ddd', 'f2'),
@@ -1768,14 +1767,12 @@ class DirTestCase(_tempdirTestCase):
 
         fs.File(os.path.join('ddd', 'f1'))
         dir.scan()
-        kids = [x.path for x in dir.children()]
-        kids.sort()
+        kids = sorted([x.path for x in dir.children()])
         assert kids == [os.path.join('ddd', 'f1')], kids
 
         fs.File(os.path.join('ddd', 'f2'))
         dir.scan()
-        kids = [x.path for x in dir.children()]
-        kids.sort()
+        kids = sorted([x.path for x in dir.children()])
         assert kids == [os.path.join('ddd', 'f1'),
                         os.path.join('ddd', 'f2')], kids
 
@@ -2240,8 +2237,7 @@ class GlobTestCase(_tempdirTestCase):
         strings_kwargs = copy.copy(kwargs)
         strings_kwargs['strings'] = True
         for input, string_expect, node_expect in cases:
-            r = self.fs.Glob(input, **strings_kwargs)
-            r.sort()
+            r = sorted(self.fs.Glob(input, **strings_kwargs))
             assert r == string_expect, "Glob(%s, strings=True) expected %s, got %s" % (input, string_expect, r)
 
         # Now execute all of the cases without string=True and look for
@@ -2256,13 +2252,12 @@ class GlobTestCase(_tempdirTestCase):
                 r.sort(lambda a,b: cmp(a.path, b.path))
                 result = []
                 for n in node_expect:
-                    if type(n) == type(''):
+                    if isinstance(n, str):
                         n = self.fs.Entry(n)
                     result.append(n)
                 fmt = lambda n: "%s %s" % (repr(n), repr(str(n)))
             else:
-                r = list(map(str, r))
-                r.sort()
+                r = sorted(map(str, r))
                 result = string_expect
                 fmt = lambda n: n
             if r != result:
diff --git a/src/engine/SCons/Node/NodeTests.py b/src/engine/SCons/Node/NodeTests.py
index 0784237..6b76e9a 100644
--- a/src/engine/SCons/Node/NodeTests.py
+++ b/src/engine/SCons/Node/NodeTests.py
@@ -27,7 +27,6 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 import os
 import re
 import sys
-import types
 import unittest
 import UserList
 
@@ -50,7 +49,7 @@ def _actionAppend(a1, a2):
             all.append(curr_a)
         elif isinstance(curr_a, MyListAction):
             all.extend(curr_a.list)
-        elif type(curr_a) == type([1,2]):
+        elif isinstance(curr_a, list):
             all.extend(curr_a)
         else:
             raise 'Cannot Combine Actions'
diff --git a/src/engine/SCons/Node/__init__.py b/src/engine/SCons/Node/__init__.py
index c25c955..455487e 100644
--- a/src/engine/SCons/Node/__init__.py
+++ b/src/engine/SCons/Node/__init__.py
@@ -136,8 +136,7 @@ class NodeInfoBase:
             try:
                 field_list = self.field_list
             except AttributeError:
-                field_list = self.__dict__.keys()
-                field_list.sort()
+                field_list = sorted(self.__dict__.keys())
         fields = []
         for field in field_list:
             try:
diff --git a/src/engine/SCons/SConf.py b/src/engine/SCons/SConf.py
index bd67ab2..e8b6c0e 100644
--- a/src/engine/SCons/SConf.py
+++ b/src/engine/SCons/SConf.py
@@ -33,7 +33,6 @@ import re
 import StringIO
 import sys
 import traceback
-import types
 
 import SCons.Action
 import SCons.Builder
@@ -154,9 +153,8 @@ def _stringSource( target, source, env ):
     return (str(target[0]) + ' <-\n  |' +
             source[0].get_contents().replace( '\n', "\n  |" ) )
 
-# python 2.2 introduces types.BooleanType
-BooleanTypes = [types.IntType]
-if hasattr(types, 'BooleanType'): BooleanTypes.append(types.BooleanType)
+# python 2.2 introduces bool
+BooleanTypes = [int, bool]
 
 class SConfBuildInfo(SCons.Node.FS.FileBuildInfo):
     """
@@ -790,7 +788,7 @@ class CheckContext:
                 text = "yes"
             else:
                 text = "no"
-        elif type(res) == types.StringType:
+        elif isinstance(res, str):
             text = res
         else:
             raise TypeError, "Expected string, int or bool, got " + str(type(res))
diff --git a/src/engine/SCons/SConfTests.py b/src/engine/SCons/SConfTests.py
index d0da84a..26f21f3 100644
--- a/src/engine/SCons/SConfTests.py
+++ b/src/engine/SCons/SConfTests.py
@@ -61,7 +61,7 @@ class SConfTestCase(unittest.TestCase):
         for n in sys.modules.keys():
             if n.split('.')[0] == 'SCons' and n[:12] != 'SCons.compat':
                 m = sys.modules[n]
-                if type(m) is ModuleType:
+                if isinstance(m, ModuleType):
                     # if this is really a scons module, clear its namespace
                     del sys.modules[n]
                     m.__dict__.clear()
diff --git a/src/engine/SCons/SConsign.py b/src/engine/SCons/SConsign.py
index a87eeeb..bd32278 100644
--- a/src/engine/SCons/SConsign.py
+++ b/src/engine/SCons/SConsign.py
@@ -202,7 +202,7 @@ class DB(Base):
         else:
             try:
                 self.entries = cPickle.loads(rawentries)
-                if type(self.entries) is not type({}):
+                if not isinstance(self.entries, dict):
                     self.entries = {}
                     raise TypeError
             except KeyboardInterrupt:
@@ -261,7 +261,7 @@ class Dir(Base):
             return
 
         self.entries = cPickle.load(fp)
-        if type(self.entries) is not type({}):
+        if not isinstance(self.entries, dict):
             self.entries = {}
             raise TypeError
 
diff --git a/src/engine/SCons/Scanner/CTests.py b/src/engine/SCons/Scanner/CTests.py
index e92af24..2869d3b 100644
--- a/src/engine/SCons/Scanner/CTests.py
+++ b/src/engine/SCons/Scanner/CTests.py
@@ -190,7 +190,7 @@ class DummyEnvironment(UserDict.UserDict):
         return [[strSubst]]
 
     def subst_path(self, path, target=None, source=None, conv=None):
-        if type(path) != type([]):
+        if not isinstance(path, list):
             path = [path]
         return list(map(self.subst, path))
 
diff --git a/src/engine/SCons/Scanner/Dir.py b/src/engine/SCons/Scanner/Dir.py
index 6b7f05b..3a0767a 100644
--- a/src/engine/SCons/Scanner/Dir.py
+++ b/src/engine/SCons/Scanner/Dir.py
@@ -101,8 +101,7 @@ def scan_in_memory(node, env, path=()):
         # mixed Node types (Dirs and Files, for example) has a Dir as
         # the first entry.
         return []
-    entry_list = list(filter(do_not_scan, entries.keys()))
-    entry_list.sort()
+    entry_list = sorted(filter(do_not_scan, entries.keys()))
     return [entries[n] for n in entry_list]
 
 # Local Variables:
diff --git a/src/engine/SCons/Scanner/DirTests.py b/src/engine/SCons/Scanner/DirTests.py
index 0ad1cfe..1e45e26 100644
--- a/src/engine/SCons/Scanner/DirTests.py
+++ b/src/engine/SCons/Scanner/DirTests.py
@@ -25,7 +25,6 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import os.path
 import sys
-import types
 import unittest
 
 import TestCmd
diff --git a/src/engine/SCons/Scanner/Fortran.py b/src/engine/SCons/Scanner/Fortran.py
index fd6a014..74f44bc 100644
--- a/src/engine/SCons/Scanner/Fortran.py
+++ b/src/engine/SCons/Scanner/Fortran.py
@@ -123,9 +123,7 @@ class F90Scanner(SCons.Scanner.Classic):
                 sortkey = self.sort_key(dep)
                 nodes.append((sortkey, n))
 
-        nodes.sort()
-        nodes = [pair[1] for pair in nodes]
-        return nodes
+        return [pair[1] for pair in sorted(nodes)]
 
 def FortranScan(path_variable="FORTRANPATH"):
     """Return a prototype Scanner instance for scanning source files
diff --git a/src/engine/SCons/Scanner/FortranTests.py b/src/engine/SCons/Scanner/FortranTests.py
index 0380e87..b75da58 100644
--- a/src/engine/SCons/Scanner/FortranTests.py
+++ b/src/engine/SCons/Scanner/FortranTests.py
@@ -238,7 +238,7 @@ class DummyEnvironment:
         return arg
 
     def subst_path(self, path, target=None, source=None, conv=None):
-        if type(path) != type([]):
+        if not isinstance(path, list):
             path = [path]
         return list(map(self.subst, path))
 
diff --git a/src/engine/SCons/Scanner/IDLTests.py b/src/engine/SCons/Scanner/IDLTests.py
index 26b3956..096fc9f 100644
--- a/src/engine/SCons/Scanner/IDLTests.py
+++ b/src/engine/SCons/Scanner/IDLTests.py
@@ -203,7 +203,7 @@ class DummyEnvironment:
         return arg
 
     def subst_path(self, path, target=None, source=None, conv=None):
-        if type(path) != type([]):
+        if not isinstance(path, list):
             path = [path]
         return list(map(self.subst, path))
 
diff --git a/src/engine/SCons/Scanner/LaTeX.py b/src/engine/SCons/Scanner/LaTeX.py
index f3085d1..622f2a3 100644
--- a/src/engine/SCons/Scanner/LaTeX.py
+++ b/src/engine/SCons/Scanner/LaTeX.py
@@ -365,10 +365,7 @@ class LaTeX(SCons.Scanner.Base):
                 # recurse down 
                 queue.extend( self.scan(n) )
 
-        #
-        nodes.sort()
-        nodes = [pair[1] for pair in nodes]
-        return nodes
+        return [pair[1] for pair in sorted(nodes)]
 
 # Local Variables:
 # tab-width:4
diff --git a/src/engine/SCons/Scanner/LaTeXTests.py b/src/engine/SCons/Scanner/LaTeXTests.py
index ac978cf..4ded0b8 100644
--- a/src/engine/SCons/Scanner/LaTeXTests.py
+++ b/src/engine/SCons/Scanner/LaTeXTests.py
@@ -25,7 +25,6 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import os.path
 import sys
-import types
 import unittest
 import UserDict
 
@@ -85,7 +84,7 @@ class DummyEnvironment(UserDict.UserDict):
         return [[strSubst]]
 
     def subst_path(self, path, target=None, source=None, conv=None):
-        if type(path) != type([]):
+        if not isinstance(path, list):
             path = [path]
         return list(map(self.subst, path))
 
diff --git a/src/engine/SCons/Scanner/ProgTests.py b/src/engine/SCons/Scanner/ProgTests.py
index ee62ca7..2b02c90 100644
--- a/src/engine/SCons/Scanner/ProgTests.py
+++ b/src/engine/SCons/Scanner/ProgTests.py
@@ -25,7 +25,6 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import os.path
 import sys
-import types
 import unittest
 
 import TestCmd
@@ -79,7 +78,7 @@ class DummyEnvironment:
         return s
 
     def subst_path(self, path, target=None, source=None, conv=None):
-        if type(path) != type([]):
+        if not isinstance(path, list):
             path = [path]
         return list(map(self.subst, path))
 
@@ -101,8 +100,7 @@ class DummyNode:
         return self.name
     
 def deps_match(deps, libs):
-    deps=list(map(str, deps))
-    deps.sort()
+    deps=sorted(map(str, deps))
     libs.sort()
     return list(map(os.path.normpath, deps)) == list(map(os.path.normpath, libs))
 
@@ -232,7 +230,9 @@ def suite():
     suite.addTest(ProgramScannerTestCase6())
     suite.addTest(ProgramScannerTestCase7())
     suite.addTest(ProgramScannerTestCase8())
-    if hasattr(types, 'UnicodeType'):
+    try: unicode
+    except NameError: pass
+    else:
         code = """if 1:
             class ProgramScannerTestCase4(unittest.TestCase):
                 def runTest(self):
diff --git a/src/engine/SCons/Scanner/RCTests.py b/src/engine/SCons/Scanner/RCTests.py
index a20c919..60af3b4 100644
--- a/src/engine/SCons/Scanner/RCTests.py
+++ b/src/engine/SCons/Scanner/RCTests.py
@@ -86,7 +86,7 @@ class DummyEnvironment(UserDict.UserDict):
         return strSubst
 
     def subst_path(self, path, target=None, source=None, conv=None):
-        if type(path) != type([]):
+        if not isinstance(path, list):
             path = [path]
         return list(map(self.subst, path))
 
@@ -112,10 +112,8 @@ if os.path.normcase('foo') == os.path.normcase('FOO'):
     my_normpath = os.path.normcase
 
 def deps_match(self, deps, headers):
-    scanned = list(map(my_normpath, list(map(str, deps))))
-    expect = list(map(my_normpath, headers))
-    scanned.sort()
-    expect.sort()
+    scanned = sorted(map(my_normpath, list(map(str, deps))))
+    expect = sorted(map(my_normpath, headers))
     self.failUnless(scanned == expect, "expect %s != scanned %s" % (expect, scanned))
 
 # define some tests:
diff --git a/src/engine/SCons/Scanner/ScannerTests.py b/src/engine/SCons/Scanner/ScannerTests.py
index d89fb14..500ce1a 100644
--- a/src/engine/SCons/Scanner/ScannerTests.py
+++ b/src/engine/SCons/Scanner/ScannerTests.py
@@ -48,7 +48,7 @@ class DummyEnvironment(UserDict.UserDict):
             return [self.data[strSubst[1:]]]
         return [[strSubst]]
     def subst_path(self, path, target=None, source=None, conv=None):
-        if type(path) != type([]):
+        if not isinstance(path, list):
             path = [path]
         return list(map(self.subst, path))
     def get_factory(self, factory):
@@ -134,7 +134,7 @@ class BaseTestCase(unittest.TestCase):
         self.failUnless(self.env == env, "the environment was passed incorrectly")
         self.failUnless(scanned_strs == deps, "the dependencies were returned incorrectly")
         for d in scanned:
-            self.failUnless(type(d) != type(""), "got a string in the dependencies")
+            self.failUnless(not isinstance(d, str), "got a string in the dependencies")
 
         if len(args) > 0:
             self.failUnless(self.arg == args[0], "the argument was passed incorrectly")
diff --git a/src/engine/SCons/Scanner/__init__.py b/src/engine/SCons/Scanner/__init__.py
index be08256..3cfe4b7 100644
--- a/src/engine/SCons/Scanner/__init__.py
+++ b/src/engine/SCons/Scanner/__init__.py
@@ -378,12 +378,9 @@ class Classic(Current):
                 SCons.Warnings.warn(SCons.Warnings.DependencyWarning,
                                     "No dependency generated for file: %s (included from: %s) -- file not found" % (i, node))
             else:
-                sortkey = self.sort_key(include)
-                nodes.append((sortkey, n))
+                nodes.append((self.sort_key(include), n))
 
-        nodes.sort()
-        nodes = [pair[1] for pair in nodes]
-        return nodes
+        return [pair[1] for pair in sorted(nodes)]
 
 class ClassicCPP(Classic):
     """
diff --git a/src/engine/SCons/Script/Main.py b/src/engine/SCons/Script/Main.py
index 7173f1b..55ac598 100644
--- a/src/engine/SCons/Script/Main.py
+++ b/src/engine/SCons/Script/Main.py
@@ -316,11 +316,7 @@ class CleanTask(SCons.Taskmaster.AlwaysTask):
                     display("Removed " + pathstr)
                 elif os.path.isdir(path) and not os.path.islink(path):
                     # delete everything in the dir
-                    entries = os.listdir(path)
-                    # Sort for deterministic output (os.listdir() Can
-                    # return entries in a random order).
-                    entries.sort()
-                    for e in entries:
+                    for e in sorted(os.listdir(path)):
                         p = os.path.join(path, e)
                         s = os.path.join(pathstr, e)
                         if os.path.isfile(p):
@@ -508,8 +504,6 @@ class CountStats(Stats):
             for n, c in s:
                 stats_table[n][i] = c
             i = i + 1
-        keys = stats_table.keys()
-        keys.sort()
         self.outfp.write("Object counts:\n")
         pre = ["   "]
         post = ["   %s\n"]
@@ -520,7 +514,7 @@ class CountStats(Stats):
         labels.append(("", "Class"))
         self.outfp.write(fmt1 % tuple([x[0] for x in labels]))
         self.outfp.write(fmt1 % tuple([x[1] for x in labels]))
-        for k in keys:
+        for k in sorted(stats_table.keys()):
             r = stats_table[k][:l] + [k]
             self.outfp.write(fmt2 % tuple(r))
 
@@ -1228,7 +1222,7 @@ def _exec_main(parser, values):
 
     options, args = parser.parse_args(all_args, values)
 
-    if type(options.debug) == type([]) and "pdb" in options.debug:
+    if isinstance(options.debug, list) and "pdb" in options.debug:
         import pdb
         pdb.Pdb().runcall(_main, parser)
     elif options.profile_file:
diff --git a/src/engine/SCons/Script/SConscript.py b/src/engine/SCons/Script/SConscript.py
index 1021921..c55d220 100644
--- a/src/engine/SCons/Script/SConscript.py
+++ b/src/engine/SCons/Script/SConscript.py
@@ -51,7 +51,6 @@ import os.path
 import re
 import sys
 import traceback
-import types
 import UserList
 
 # The following variables used to live in this module.  Some
@@ -629,7 +628,7 @@ def BuildDefaultGlobals():
         import SCons.Script
         d = SCons.Script.__dict__
         def not_a_module(m, d=d, mtype=type(SCons.Script)):
-             return type(d[m]) != mtype
+             return not isinstance(d[m], mtype)
         for m in filter(not_a_module, dir(SCons.Script)):
              GlobalDict[m] = d[m]
 
diff --git a/src/engine/SCons/Subst.py b/src/engine/SCons/Subst.py
index 936348a..9888e8d 100644
--- a/src/engine/SCons/Subst.py
+++ b/src/engine/SCons/Subst.py
@@ -31,7 +31,6 @@ from __future__ import generators  ### KEEP FOR COMPATIBILITY FIXERS
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import re
-import types
 import UserList
 import UserString
 
@@ -399,7 +398,7 @@ def scons_subst(strSubst, env, mode=SUBST_RAW, target=None, source=None, gvars={
     handles separating command lines into lists of arguments, so see
     that function if that's what you're looking for.
     """
-    if type(strSubst) == types.StringType and strSubst.find('$') < 0:
+    if isinstance(strSubst, str) and strSubst.find('$') < 0:
         return strSubst
 
     class StringSubber:
@@ -870,7 +869,7 @@ def scons_subst_once(strSubst, env, key):
 
     We do this with some straightforward, brute-force code here...
     """
-    if type(strSubst) == types.StringType and strSubst.find('$') < 0:
+    if isinstance(strSubst, str) and strSubst.find('$') < 0:
         return strSubst
 
     matchlist = ['$' + key, '${' + key + '}']
diff --git a/src/engine/SCons/SubstTests.py b/src/engine/SCons/SubstTests.py
index b587dfa..2eb91ca 100644
--- a/src/engine/SCons/SubstTests.py
+++ b/src/engine/SCons/SubstTests.py
@@ -29,7 +29,6 @@ import os
 import os.path
 import StringIO
 import sys
-import types
 import unittest
 
 from UserDict import UserDict
@@ -150,7 +149,7 @@ class SubstTestCase(unittest.TestCase):
     def _defines(defs):
         l = []
         for d in defs:
-            if SCons.Util.is_List(d) or type(d) is types.TupleType:
+            if SCons.Util.is_List(d) or isinstance(d, tuple):
                 l.append(str(d[0]) + '=' + str(d[1]))
             else:
                 l.append(str(d))
diff --git a/src/engine/SCons/Taskmaster.py b/src/engine/SCons/Taskmaster.py
index 66bcdfa..b2c4204 100644
--- a/src/engine/SCons/Taskmaster.py
+++ b/src/engine/SCons/Taskmaster.py
@@ -737,7 +737,7 @@ class Taskmaster:
         T = self.trace
         if T: T.write('\n' + self.trace_message('Looking for a node to evaluate'))
 
-        while 1:
+        while True:
             node = self.next_candidate()
             if node is None:
                 if T: T.write(self.trace_message('No candidate anymore.') + '\n')
@@ -952,7 +952,7 @@ class Taskmaster:
                 T.write(self.trace_message('       removing node %s from the pending children set\n' %
                         self.trace_node(n)))
         try:
-            while 1:
+            while True:
                 try:
                     node = to_visit.pop()
                 except AttributeError:
diff --git a/src/engine/SCons/TaskmasterTests.py b/src/engine/SCons/TaskmasterTests.py
index 4a0e13a..65d10b5 100644
--- a/src/engine/SCons/TaskmasterTests.py
+++ b/src/engine/SCons/TaskmasterTests.py
@@ -910,7 +910,7 @@ class TaskmasterTestCase(unittest.TestCase):
             assert e.errstr == "OtherError : ", e.errstr
             assert len(e.exc_info) == 3, e.exc_info
             exc_traceback = sys.exc_info()[2]
-            assert type(e.exc_info[2]) == type(exc_traceback), e.exc_info[2]
+            assert isinstance(e.exc_info[2], type(exc_traceback)), e.exc_info[2]
         else:
             raise TestFailed, "did not catch expected BuildError"
 
diff --git a/src/engine/SCons/Tool/intelc.py b/src/engine/SCons/Tool/intelc.py
index e193695..1cc1312 100644
--- a/src/engine/SCons/Tool/intelc.py
+++ b/src/engine/SCons/Tool/intelc.py
@@ -243,9 +243,7 @@ def get_all_compiler_versions():
             m = re.search(r'([0-9.]+)$', d)
             if m:
                 versions.append(m.group(1))
-    versions = uniquify(versions)       # remove dups
-    versions.sort(vercmp)
-    return versions
+    return sorted(uniquify(versions))       # remove dups
 
 def get_intel_compiler_top(version, abi):
     """
diff --git a/src/engine/SCons/Tool/javac.py b/src/engine/SCons/Tool/javac.py
index d080af5..ef4bd5b 100644
--- a/src/engine/SCons/Tool/javac.py
+++ b/src/engine/SCons/Tool/javac.py
@@ -74,10 +74,7 @@ def emit_java_classes(target, source, env):
         elif isinstance(entry, SCons.Node.FS.Dir):
             result = SCons.Util.OrderedDict()
             def visit(arg, dirname, names, dirnode=entry.rdir()):
-                java_files = [n for n in names if _my_normcase(n[-len(js):]) == js]
-                # The on-disk entries come back in arbitrary order.  Sort
-                # them so our target and source lists are determinate.
-                java_files.sort()
+                java_files = sorted([n for n in names if _my_normcase(n[-len(js):]) == js])
                 mydir = dirnode.Dir(dirname)
                 java_paths = [mydir.File(f) for f in java_files]
                 for jp in java_paths:
diff --git a/src/engine/SCons/Tool/msvs.py b/src/engine/SCons/Tool/msvs.py
index 57098a8..c5e93ac 100644
--- a/src/engine/SCons/Tool/msvs.py
+++ b/src/engine/SCons/Tool/msvs.py
@@ -291,8 +291,6 @@ class _DSPGenerator:
                         self.sources[t[0]].append(self.env[t[1]])
 
         for n in sourcenames:
-            # TODO(1.5):
-            #self.sources[n].sort(lambda a, b: cmp(a.lower(), b.lower()))
             self.sources[n].sort(lambda a, b: cmp(a.lower(), b.lower()))
 
         def AddConfig(self, variant, buildtarget, outdir, runfile, cmdargs, dspfile=dspfile):
@@ -352,8 +350,7 @@ class _GenerateV6DSP(_DSPGenerator):
 
     def PrintHeader(self):
         # pick a default config
-        confkeys = self.configs.keys()
-        confkeys.sort()
+        confkeys = sorted(self.configs.keys())
 
         name = self.name
         confkey = confkeys[0]
@@ -373,8 +370,7 @@ class _GenerateV6DSP(_DSPGenerator):
                         '# PROP Scc_LocalPath ""\n\n')
 
         first = 1
-        confkeys = self.configs.keys()
-        confkeys.sort()
+        confkeys = sorted(self.configs.keys())
         for kind in confkeys:
             outdir = self.configs[kind].outdir
             buildtarget = self.configs[kind].buildtarget
@@ -445,8 +441,6 @@ class _GenerateV6DSP(_DSPGenerator):
                       'Other Files': ''}
 
         cats = categories.keys()
-        # TODO(1.5):
-        #cats.sort(lambda a, b: cmp(a.lower(), b.lower()))
         cats.sort(lambda a, b: cmp(a.lower(), b.lower()))
         for kind in cats:
             if not self.sources[kind]:
@@ -649,8 +643,7 @@ class _GenerateV7DSP(_DSPGenerator):
     def PrintProject(self):
         self.file.write('\t<Configurations>\n')
 
-        confkeys = self.configs.keys()
-        confkeys.sort()
+        confkeys = sorted(self.configs.keys())
         for kind in confkeys:
             variant = self.configs[kind].variant
             platform = self.configs[kind].platform
@@ -704,8 +697,6 @@ class _GenerateV7DSP(_DSPGenerator):
 
     def printSources(self, hierarchy, commonprefix):
         sorteditems = hierarchy.items()
-        # TODO(1.5):
-        #sorteditems.sort(lambda a, b: cmp(a[0].lower(), b[0].lower()))
         sorteditems.sort(lambda a, b: cmp(a[0].lower(), b[0].lower()))
 
         # First folders, then files
@@ -737,8 +728,6 @@ class _GenerateV7DSP(_DSPGenerator):
         self.file.write('\t<Files>\n')
 
         cats = categories.keys()
-        # TODO(1.5)
-        #cats.sort(lambda a, b: cmp(a.lower(), b.lower()))
         cats.sort(lambda a, b: cmp(a.lower(), b.lower()))
         cats = [k for k in cats if self.sources[k]]
         for kind in cats:
@@ -1007,8 +996,7 @@ class _GenerateV7DSW(_DSWGenerator):
         else:
             self.file.write('\tGlobalSection(SolutionConfiguration) = preSolution\n')
 
-        confkeys = self.configs.keys()
-        confkeys.sort()
+        confkeys = sorted(self.configs.keys())
         cnt = 0
         for name in confkeys:
             variant = self.configs[name].variant
diff --git a/src/engine/SCons/Tool/mwcc.py b/src/engine/SCons/Tool/mwcc.py
index c720956..8f1201a 100644
--- a/src/engine/SCons/Tool/mwcc.py
+++ b/src/engine/SCons/Tool/mwcc.py
@@ -99,7 +99,7 @@ def find_versions():
             product_key = SCons.Util.RegOpenKeyEx(HLM, product)
 
             i = 0
-            while 1:
+            while True:
                 name = product + '\\' + SCons.Util.RegEnumKey(product_key, i)
                 name_key = SCons.Util.RegOpenKeyEx(HLM, name)
 
diff --git a/src/engine/SCons/Util.py b/src/engine/SCons/Util.py
index a373863..f8bac89 100644
--- a/src/engine/SCons/Util.py
+++ b/src/engine/SCons/Util.py
@@ -42,11 +42,14 @@ from UserString import UserString
 
 # Don't "from types import ..." these because we need to get at the
 # types module later to look for UnicodeType.
-DictType        = types.DictType
+DictType        = dict
 InstanceType    = types.InstanceType
-ListType        = types.ListType
-StringType      = types.StringType
-TupleType       = types.TupleType
+ListType        = list
+StringType      = str
+TupleType       = tuple
+try: unicode
+except NameError: UnicodeType = None
+else:             UnicodeType = unicode
 
 def dictify(keys, values, result={}):
     for k, v in zip(keys, values):
@@ -343,7 +346,7 @@ except TypeError:
         t = type(obj)
         return t is TupleType
 
-    if hasattr(types, 'UnicodeType'):
+    if UnicodeType is not None:
         def is_String(obj):
             t = type(obj)
             return t is StringType \
@@ -398,8 +401,7 @@ except TypeError:
     # to_String_for_signature() will use a for_signature() method if the
     # specified object has one.
     #
-    if hasattr(types, 'UnicodeType'):
-        UnicodeType = types.UnicodeType
+    if UnicodeType is not None:
         def to_String(s):
             if isinstance(s, UserString):
                 t = type(s.data)
@@ -595,15 +597,15 @@ def _semi_deepcopy_dict(x):
         # Doesn't seem like we need to, but we'll comment it just in case.
         copy[key] = semi_deepcopy(val)
     return copy
-d[types.DictionaryType] = _semi_deepcopy_dict
+d[dict] = _semi_deepcopy_dict
 
 def _semi_deepcopy_list(x):
     return list(map(semi_deepcopy, x))
-d[types.ListType] = _semi_deepcopy_list
+d[list] = _semi_deepcopy_list
 
 def _semi_deepcopy_tuple(x):
     return tuple(map(semi_deepcopy, x))
-d[types.TupleType] = _semi_deepcopy_tuple
+d[tuple] = _semi_deepcopy_tuple
 
 def _semi_deepcopy_inst(x):
     if hasattr(x, '__semi_deepcopy__'):
@@ -1220,8 +1222,7 @@ def unique(s):
     # sort functions in all languages or libraries, so this approach
     # is more effective in Python than it may be elsewhere.
     try:
-        t = list(s)
-        t.sort()
+        t = sorted(s)
     except TypeError:
         pass    # move on to the next method
     else:
@@ -1291,7 +1292,7 @@ class LogicalLines:
 
     def readline(self):
         result = []
-        while 1:
+        while True:
             line = self.fileobj.readline()
             if not line:
                 break
@@ -1304,7 +1305,7 @@ class LogicalLines:
 
     def readlines(self):
         result = []
-        while 1:
+        while True:
             line = self.readline()
             if not line:
                 break
@@ -1545,7 +1546,7 @@ else:
         def MD5filesignature(fname, chunksize=65536):
             m = hashlib.md5()
             f = open(fname, "rb")
-            while 1:
+            while True:
                 blck = f.read(chunksize)
                 if not blck:
                     break
diff --git a/src/engine/SCons/UtilTests.py b/src/engine/SCons/UtilTests.py
index 670fc83..ad27127 100644
--- a/src/engine/SCons/UtilTests.py
+++ b/src/engine/SCons/UtilTests.py
@@ -27,7 +27,6 @@ import os
 import os.path
 import StringIO
 import sys
-import types
 import unittest
 
 from UserDict import UserDict
@@ -38,6 +37,10 @@ import SCons.Errors
 
 from SCons.Util import *
 
+try: unicode
+except NameError: HasUnicode = False
+else:             HasUnicode = True
+
 class OutBuffer:
     def __init__(self):
         self.buffer = ""
@@ -214,7 +217,7 @@ class UtilTestCase(unittest.TestCase):
         assert not is_Dict([])
         assert not is_Dict(())
         assert not is_Dict("")
-        if hasattr(types, 'UnicodeType'):
+        if HasUnicode:
             exec "assert not is_Dict(u'')"
 
     def test_is_List(self):
@@ -231,12 +234,12 @@ class UtilTestCase(unittest.TestCase):
         assert not is_List(())
         assert not is_List({})
         assert not is_List("")
-        if hasattr(types, 'UnicodeType'):
+        if HasUnicode:
             exec "assert not is_List(u'')"
 
     def test_is_String(self):
         assert is_String("")
-        if hasattr(types, 'UnicodeType'):
+        if HasUnicode:
             exec "assert is_String(u'')"
         try:
             import UserString
@@ -267,7 +270,7 @@ class UtilTestCase(unittest.TestCase):
         assert not is_Tuple([])
         assert not is_Tuple({})
         assert not is_Tuple("")
-        if hasattr(types, 'UnicodeType'):
+        if HasUnicode:
             exec "assert not is_Tuple(u'')"
 
     def test_to_String(self):
@@ -289,19 +292,19 @@ class UtilTestCase(unittest.TestCase):
             assert to_String(s2) == s2, s2
             assert to_String(s2) == 'foo', s2
 
-            if hasattr(types, 'UnicodeType'):
+            if HasUnicode:
                 s3=UserString.UserString(unicode('bar'))
                 assert to_String(s3) == s3, s3
                 assert to_String(s3) == unicode('bar'), s3
-                assert type(to_String(s3)) is types.UnicodeType, \
+                assert isinstance(to_String(s3), unicode), \
                        type(to_String(s3))
         except ImportError:
             pass
 
-        if hasattr(types, 'UnicodeType'):
+        if HasUnicode:
             s4 = unicode('baz')
             assert to_String(s4) == unicode('baz'), to_String(s4)
-            assert type(to_String(s4)) is types.UnicodeType, \
+            assert isinstance(to_String(s4), unicode), \
                    type(to_String(s4))
 
     def test_WhereIs(self):
diff --git a/src/engine/SCons/Variables/ListVariable.py b/src/engine/SCons/Variables/ListVariable.py
index 36b530a..5980f33 100644
--- a/src/engine/SCons/Variables/ListVariable.py
+++ b/src/engine/SCons/Variables/ListVariable.py
@@ -63,8 +63,7 @@ import SCons.Util
 class _ListVariable(UserList.UserList):
     def __init__(self, initlist=[], allowedElems=[]):
         UserList.UserList.__init__(self, [_f for _f in initlist if _f])
-        self.allowedElems = allowedElems[:]
-        self.allowedElems.sort()
+        self.allowedElems = sorted(allowedElems)
 
     def __cmp__(self, other):
         raise NotImplementedError
diff --git a/src/engine/SCons/Variables/__init__.py b/src/engine/SCons/Variables/__init__.py
index 27f694f..09d4e29 100644
--- a/src/engine/SCons/Variables/__init__.py
+++ b/src/engine/SCons/Variables/__init__.py
@@ -123,7 +123,7 @@ class Variables:
                     putting it in the environment.
         """
 
-        if SCons.Util.is_List(key) or type(key) == type(()):
+        if SCons.Util.is_List(key) or isinstance(key, tuple):
             self._do_add(*key)
             return
 
@@ -284,8 +284,7 @@ class Variables:
         """
 
         if sort:
-            options = self.options[:]
-            options.sort(lambda x,y: sort(x.key,y.key))
+            options = sorted(self.options, cmp=lambda x,y: sort(x.key,y.key))
         else:
             options = self.options
 
diff --git a/src/engine/SCons/compat/_scons_UserString.py b/src/engine/SCons/compat/_scons_UserString.py
index 785a260..dfc2b30 100644
--- a/src/engine/SCons/compat/_scons_UserString.py
+++ b/src/engine/SCons/compat/_scons_UserString.py
@@ -33,17 +33,13 @@ In particular, it does not necessarily contain all of the methods found
 in later versions.
 """
 
-import types
-
-StringType = types.StringType
-
-if hasattr(types, 'UnicodeType'):
-    UnicodeType = types.UnicodeType
+try: unicode
+except NameError:
     def is_String(obj):
-        return type(obj) in (StringType, UnicodeType)
+        return type(obj) is str
 else:
     def is_String(obj):
-        return type(obj) is StringType
+        return type(obj) in (str, unicode)
 
 class UserString:
     def __init__(self, seq):
diff --git a/src/engine/SCons/compat/_scons_optparse.py b/src/engine/SCons/compat/_scons_optparse.py
index 5db4c90..ac5b448 100644
--- a/src/engine/SCons/compat/_scons_optparse.py
+++ b/src/engine/SCons/compat/_scons_optparse.py
@@ -643,8 +643,7 @@ class Option:
                 else:
                     setattr(self, attr, None)
         if attrs:
-            attrs = attrs.keys()
-            attrs.sort()
+            attrs = sorted(attrs.keys())
             raise OptionError(
                 "invalid keyword arguments: %s" % string.join(attrs, ", "),
                 self)
@@ -693,7 +692,7 @@ class Option:
             if self.choices is None:
                 raise OptionError(
                     "must supply a list of choices for type 'choice'", self)
-            elif type(self.choices) not in (types.TupleType, types.ListType):
+            elif type(self.choices) not in (tuple, list):
                 raise OptionError(
                     "choices must be a list of strings ('%s' supplied)"
                     % string.split(str(type(self.choices)), "'")[1], self)
@@ -737,12 +736,12 @@ class Option:
                 raise OptionError(
                     "callback not callable: %r" % self.callback, self)
             if (self.callback_args is not None and
-                type(self.callback_args) is not types.TupleType):
+                type(self.callback_args) is not tuple):
                 raise OptionError(
                     "callback_args, if supplied, must be a tuple: not %r"
                     % self.callback_args, self)
             if (self.callback_kwargs is not None and
-                type(self.callback_kwargs) is not types.DictType):
+                type(self.callback_kwargs) is not dict):
                 raise OptionError(
                     "callback_kwargs, if supplied, must be a dict: not %r"
                     % self.callback_kwargs, self)
@@ -855,14 +854,13 @@ try:
 except NameError:
     (True, False) = (1, 0)
 
-try:
-    types.UnicodeType
-except AttributeError:
+try: unicode
+except NameError:
     def isbasestring(x):
-        return isinstance(x, types.StringType)
+        return isinstance(x, str)
 else:
     def isbasestring(x):
-        return isinstance(x, types.StringType) or isinstance(x, types.UnicodeType)
+        return isinstance(x, str) or isinstance(x, unicode)
 
 class Values:
 
@@ -879,7 +877,7 @@ class Values:
     def __cmp__(self, other):
         if isinstance(other, Values):
             return cmp(self.__dict__, other.__dict__)
-        elif isinstance(other, types.DictType):
+        elif isinstance(other, dict):
             return cmp(self.__dict__, other)
         else:
             return -1
@@ -1040,7 +1038,7 @@ class OptionContainer:
         """add_option(Option)
            add_option(opt_str, ..., kwarg=val, ...)
         """
-        if type(args[0]) is types.StringType:
+        if type(args[0]) is str:
             option = apply(self.option_class, args, kwargs)
         elif len(args) == 1 and not kwargs:
             option = args[0]
@@ -1351,7 +1349,7 @@ class OptionParser (OptionContainer):
 
     def add_option_group(self, *args, **kwargs):
         # XXX lots of overlap with OptionContainer.add_option()
-        if type(args[0]) is types.StringType:
+        if type(args[0]) is str:
             group = apply(OptionGroup, (self,) + args, kwargs)
         elif len(args) == 1 and not kwargs:
             group = args[0]
diff --git a/src/engine/SCons/compat/_scons_sets.py b/src/engine/SCons/compat/_scons_sets.py
index 12dbead..713d6e9 100644
--- a/src/engine/SCons/compat/_scons_sets.py
+++ b/src/engine/SCons/compat/_scons_sets.py
@@ -110,9 +110,9 @@ class BaseSet(object):
     # __str__ is the same as __repr__
     __str__ = __repr__
 
-    def _repr(self, sorted=False):
+    def _repr(self, sort_them=False):
         elements = self._data.keys()
-        if sorted:
+        if sort_them:
             elements.sort()
         return '%s(%r)' % (self.__class__.__name__, elements)
 
diff --git a/src/engine/SCons/compat/builtins.py b/src/engine/SCons/compat/builtins.py
index 064415e..02b94f3 100644
--- a/src/engine/SCons/compat/builtins.py
+++ b/src/engine/SCons/compat/builtins.py
@@ -152,25 +152,19 @@ except NameError:
     # we must implement the functionality of those keyword arguments
     # by hand instead of passing them to list.sort().
     def sorted(iterable, cmp=None, key=None, reverse=False):
-        if key:
-            decorated = [ (key(x), x) for x in iterable ]
-            if cmp is None:
-                # Pre-2.3 Python does not support list.sort(None).
-                decorated.sort()
-            else:
-                decorated.sort(cmp)
-            if reverse:
-                decorated.reverse()
-            result = [ t[1] for t in decorated ]
+        if key is not None:
+            result = [(key(x), x) for x in iterable]
         else:
             result = iterable[:]
-            if cmp is None:
-                # Pre-2.3 Python does not support list.sort(None).
-                result.sort()
-            else:
-                result.sort(cmp)
-            if reverse:
-                result.reverse()
+        if cmp is None:
+            # Pre-2.3 Python does not support list.sort(None).
+            result.sort()
+        else:
+            result.sort(cmp)
+        if key is not None:
+            result = [t1 for t0,t1 in result]
+        if reverse:
+            result.reverse()
         return result
     __builtin__.sorted = sorted
 
diff --git a/src/engine/SCons/cpp.py b/src/engine/SCons/cpp.py
index 5ccc00e..5e159ec 100644
--- a/src/engine/SCons/cpp.py
+++ b/src/engine/SCons/cpp.py
@@ -133,8 +133,7 @@ CPP_to_Python_Ops_Sub = lambda m: CPP_to_Python_Ops_Dict[m.group(0)]
 # re module, as late as version 2.2.2, empirically matches the
 # "!" in "!=" first, instead of finding the longest match.
 # What's up with that?
-l = CPP_to_Python_Ops_Dict.keys()
-l.sort(lambda a, b: cmp(len(b), len(a)))
+l = sorted(CPP_to_Python_Ops_Dict.keys(), cmp=lambda a, b: cmp(len(b), len(a)))
 
 # Turn the list of keys into one regular expression that will allow us
 # to substitute all of the operators at once.
diff --git a/src/engine/SCons/dblite.py b/src/engine/SCons/dblite.py
index bcb2aa0..2383f1d 100644
--- a/src/engine/SCons/dblite.py
+++ b/src/engine/SCons/dblite.py
@@ -5,7 +5,6 @@ import cPickle
 import time
 import shutil
 import os
-import types
 import __builtin__
 
 keep_all_files = 00000
@@ -14,13 +13,13 @@ ignore_corrupt_dbfiles = 0
 def corruption_warning(filename):
     print "Warning: Discarding corrupt database:", filename
 
-if hasattr(types, 'UnicodeType'):
+try: unicode
+except NameError:
     def is_string(s):
-        t = type(s)
-        return t is types.StringType or t is types.UnicodeType
+        return isinstance(s, str)
 else:
     def is_string(s):
-        return type(s) is types.StringType
+        return type(s) in (str, unicode)
 
 try:
     unicode('a')
diff --git a/src/script/scons-time.py b/src/script/scons-time.py
index c75bc13..04fa573 100644
--- a/src/script/scons-time.py
+++ b/src/script/scons-time.py
@@ -59,6 +59,32 @@ except NameError:
     import __builtin__
     __builtin__.True = not 0
 
+try:
+    sorted
+except NameError:
+    # Pre-2.4 Python has no sorted() function.
+    #
+    # The pre-2.4 Python list.sort() method does not support
+    # list.sort(key=) nor list.sort(reverse=) keyword arguments, so
+    # we must implement the functionality of those keyword arguments
+    # by hand instead of passing them to list.sort().
+    def sorted(iterable, cmp=None, key=None, reverse=False):
+        if key is not None:
+            result = [(key(x), x) for x in iterable]
+        else:
+            result = iterable[:]
+        if cmp is None:
+            # Pre-2.3 Python does not support list.sort(None).
+            result.sort()
+        else:
+            result.sort(cmp)
+        if key is not None:
+            result = [t1 for t0,t1 in result]
+        if reverse:
+            result.reverse()
+        return result
+    __builtin__.sorted = sorted
+
 def make_temp_file(**kw):
     try:
         result = tempfile.mktemp(**kw)
@@ -505,9 +531,7 @@ class SConsTimer:
         """
         files = []
         for a in args:
-            g = glob.glob(a)
-            g.sort()
-            files.extend(g)
+            files.extend(sorted(glob.glob(a)))
 
         if tail:
             files = files[-tail:]
@@ -589,10 +613,7 @@ class SConsTimer:
         """
         gp = Gnuplotter(self.title, self.key_location)
 
-        indices = results.keys()
-        indices.sort()
-
-        for i in indices:
+        for i in sorted(results.keys()):
             try:
                 t = self.run_titles[i]
             except IndexError:
diff --git a/src/script/sconsign.py b/src/script/sconsign.py
index fb3bd5e..ac619a5 100644
--- a/src/script/sconsign.py
+++ b/src/script/sconsign.py
@@ -282,8 +282,7 @@ def nodeinfo_raw(name, ninfo, prefix=""):
     try:
         keys = ninfo.field_list + ['_version_id']
     except AttributeError:
-        keys = d.keys()
-        keys.sort()
+        keys = sorted(d.keys())
     l = []
     for k in keys:
         l.append('%s: %s' % (repr(k), repr(d.get(k))))
@@ -336,9 +335,7 @@ def printentries(entries, location):
                     print nodeinfo_string(name, entry.ninfo)
                 printfield(name, entry.binfo)
     else:
-        names = entries.keys()
-        names.sort()
-        for name in names:
+        for name in sorted(entries.keys()):
             entry = entries[name]
             try:
                 ninfo = entry.ninfo
@@ -402,9 +399,7 @@ class Do_SConsignDB:
                 else:
                     self.printentries(dir, val)
         else:
-            keys = db.keys()
-            keys.sort()
-            for dir in keys:
+            for dir in sorted(db.keys()):
                 self.printentries(dir, db[dir])
 
     def printentries(self, dir, val):
diff --git a/src/test_interrupts.py b/src/test_interrupts.py
index 69e7a80..21b0dea 100644
--- a/src/test_interrupts.py
+++ b/src/test_interrupts.py
@@ -90,7 +90,7 @@ for f in files:
     contents = open(os.path.join(scons_lib_dir, f)).read()
     try_except_lines = {}
     lastend = 0
-    while 1:
+    while True:
         match = tryexc_pat.search( contents, lastend )
         if match is None:
             break
diff --git a/src/test_pychecker.py b/src/test_pychecker.py
index fb60646..ad68965 100644
--- a/src/test_pychecker.py
+++ b/src/test_pychecker.py
@@ -90,10 +90,7 @@ for file in ignore:
         del u[file]
     except KeyError:
         pass
-
-files = u.keys()
-
-files.sort()
+files = sorted(u.keys())
 
 mismatches = []