merge

3 files changed, 215 insertions, 385 deletions

diff --git a/Lib/importlib/__init__.py b/Lib/importlib/__init__.py
index 22c90f24a7..d07f02ed74 100644
--- a/Lib/importlib/__init__.py
+++ b/Lib/importlib/__init__.py
@@ -68,6 +68,8 @@ def find_loader(name, path=None):
             return loader
     except KeyError:
         pass
+    except AttributeError:
+        raise ValueError('{}.__loader__ is not set'.format(name))
     return _bootstrap._find_module(name, path)
 
 
diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py
index 08d5eb4b79..e2ac7ceecb 100644
--- a/Lib/importlib/_bootstrap.py
+++ b/Lib/importlib/_bootstrap.py
@@ -48,13 +48,7 @@ def _w_long(x):
     XXX Temporary until marshal's long functions are exposed.
 
     """
-    x = int(x)
-    int_bytes = []
-    int_bytes.append(x & 0xFF)
-    int_bytes.append((x >> 8) & 0xFF)
-    int_bytes.append((x >> 16) & 0xFF)
-    int_bytes.append((x >> 24) & 0xFF)
-    return bytearray(int_bytes)
+    return (int(x) & 0xFFFFFFFF).to_bytes(4, 'little')
 
 
 # TODO: Expose from marshal
@@ -64,35 +58,25 @@ def _r_long(int_bytes):
     XXX Temporary until marshal's long function are exposed.
 
     """
-    x = int_bytes[0]
-    x |= int_bytes[1] << 8
-    x |= int_bytes[2] << 16
-    x |= int_bytes[3] << 24
-    return x
+    return int.from_bytes(int_bytes, 'little')
 
 
 def _path_join(*path_parts):
     """Replacement for os.path.join()."""
-    new_parts = []
-    for part in path_parts:
-        if not part:
-            continue
-        new_parts.append(part)
-        if part[-1] not in path_separators:
-            new_parts.append(path_sep)
-    return ''.join(new_parts[:-1])  # Drop superfluous path separator.
+    return path_sep.join([part.rstrip(path_separators)
+                          for part in path_parts if part])
 
 
 def _path_split(path):
     """Replacement for os.path.split()."""
+    if len(path_separators) == 1:
+        front, _, tail = path.rpartition(path_sep)
+        return front, tail
     for x in reversed(path):
         if x in path_separators:
-            sep = x
-            break
-    else:
-        sep = path_sep
-    front, _, tail = path.rpartition(sep)
-    return front, tail
+            front, tail = path.rsplit(x, maxsplit=1)
+            return front, tail
+    return '', path
 
 
 def _path_is_mode_type(path, mode):
@@ -237,7 +221,7 @@ class _ModuleLock:
                     self.wakeup.release()
 
     def __repr__(self):
-        return "_ModuleLock(%r) at %d" % (self.name, id(self))
+        return "_ModuleLock({!r}) at {}".format(self.name, id(self))
 
 
 class _DummyModuleLock:
@@ -258,7 +242,7 @@ class _DummyModuleLock:
         self.count -= 1
 
     def __repr__(self):
-        return "_DummyModuleLock(%r) at %d" % (self.name, id(self))
+        return "_DummyModuleLock({!r}) at {}".format(self.name, id(self))
 
 
 # The following two functions are for consumption by Python/import.c.
@@ -315,95 +299,102 @@ def _call_with_frames_removed(f, *args, **kwds):
 
 # Finder/loader utility code ###############################################
 
-"""Magic word to reject .pyc files generated by other Python versions.
-It should change for each incompatible change to the bytecode.
-
-The value of CR and LF is incorporated so if you ever read or write
-a .pyc file in text mode the magic number will be wrong; also, the
-Apple MPW compiler swaps their values, botching string constants.
-
-The magic numbers must be spaced apart at least 2 values, as the
--U interpeter flag will cause MAGIC+1 being used. They have been
-odd numbers for some time now.
-
-There were a variety of old schemes for setting the magic number.
-The current working scheme is to increment the previous value by
-10.
-
-Starting with the adoption of PEP 3147 in Python 3.2, every bump in magic
-number also includes a new "magic tag", i.e. a human readable string used
-to represent the magic number in __pycache__ directories.  When you change
-the magic number, you must also set a new unique magic tag.  Generally this
-can be named after the Python major version of the magic number bump, but
-it can really be anything, as long as it's different than anything else
-that's come before.  The tags are included in the following table, starting
-with Python 3.2a0.
-
-Known values:
- Python 1.5:   20121
- Python 1.5.1: 20121
-    Python 1.5.2: 20121
-    Python 1.6:   50428
-    Python 2.0:   50823
-    Python 2.0.1: 50823
-    Python 2.1:   60202
-    Python 2.1.1: 60202
-    Python 2.1.2: 60202
-    Python 2.2:   60717
-    Python 2.3a0: 62011
-    Python 2.3a0: 62021
-    Python 2.3a0: 62011 (!)
-    Python 2.4a0: 62041
-    Python 2.4a3: 62051
-    Python 2.4b1: 62061
-    Python 2.5a0: 62071
-    Python 2.5a0: 62081 (ast-branch)
-    Python 2.5a0: 62091 (with)
-    Python 2.5a0: 62092 (changed WITH_CLEANUP opcode)
-    Python 2.5b3: 62101 (fix wrong code: for x, in ...)
-    Python 2.5b3: 62111 (fix wrong code: x += yield)
-    Python 2.5c1: 62121 (fix wrong lnotab with for loops and
-                         storing constants that should have been removed)
-    Python 2.5c2: 62131 (fix wrong code: for x, in ... in listcomp/genexp)
-    Python 2.6a0: 62151 (peephole optimizations and STORE_MAP opcode)
-    Python 2.6a1: 62161 (WITH_CLEANUP optimization)
-    Python 3000:   3000
-                   3010 (removed UNARY_CONVERT)
-                   3020 (added BUILD_SET)
-                   3030 (added keyword-only parameters)
-                   3040 (added signature annotations)
-                   3050 (print becomes a function)
-                   3060 (PEP 3115 metaclass syntax)
-                   3061 (string literals become unicode)
-                   3071 (PEP 3109 raise changes)
-                   3081 (PEP 3137 make __file__ and __name__ unicode)
-                   3091 (kill str8 interning)
-                   3101 (merge from 2.6a0, see 62151)
-                   3103 (__file__ points to source file)
-    Python 3.0a4: 3111 (WITH_CLEANUP optimization).
-    Python 3.0a5: 3131 (lexical exception stacking, including POP_EXCEPT)
-    Python 3.1a0: 3141 (optimize list, set and dict comprehensions:
-            change LIST_APPEND and SET_ADD, add MAP_ADD)
-    Python 3.1a0: 3151 (optimize conditional branches:
-            introduce POP_JUMP_IF_FALSE and POP_JUMP_IF_TRUE)
-    Python 3.2a0: 3160 (add SETUP_WITH)
-                  tag: cpython-32
-    Python 3.2a1: 3170 (add DUP_TOP_TWO, remove DUP_TOPX and ROT_FOUR)
-                  tag: cpython-32
-    Python 3.2a2  3180 (add DELETE_DEREF)
-    Python 3.3a0  3190 __class__ super closure changed
-    Python 3.3a0  3200 (__qualname__ added)
-                     3210 (added size modulo 2**32 to the pyc header)
-    Python 3.3a1  3220 (changed PEP 380 implementation)
-    Python 3.3a4  3230 (revert changes to implicit __class__ closure)
-
-MAGIC must change whenever the bytecode emitted by the compiler may no
-longer be understood by older implementations of the eval loop (usually
-due to the addition of new opcodes).
+# Magic word to reject .pyc files generated by other Python versions.
+# It should change for each incompatible change to the bytecode.
+#
+# The value of CR and LF is incorporated so if you ever read or write
+# a .pyc file in text mode the magic number will be wrong; also, the
+# Apple MPW compiler swaps their values, botching string constants.
+#
+# The magic numbers must be spaced apart at least 2 values, as the
+# -U interpeter flag will cause MAGIC+1 being used. They have been
+# odd numbers for some time now.
+#
+# There were a variety of old schemes for setting the magic number.
+# The current working scheme is to increment the previous value by
+# 10.
+#
+# Starting with the adoption of PEP 3147 in Python 3.2, every bump in magic
+# number also includes a new "magic tag", i.e. a human readable string used
+# to represent the magic number in __pycache__ directories.  When you change
+# the magic number, you must also set a new unique magic tag.  Generally this
+# can be named after the Python major version of the magic number bump, but
+# it can really be anything, as long as it's different than anything else
+# that's come before.  The tags are included in the following table, starting
+# with Python 3.2a0.
+#
+# Known values:
+#  Python 1.5:   20121
+#  Python 1.5.1: 20121
+#     Python 1.5.2: 20121
+#     Python 1.6:   50428
+#     Python 2.0:   50823
+#     Python 2.0.1: 50823
+#     Python 2.1:   60202
+#     Python 2.1.1: 60202
+#     Python 2.1.2: 60202
+#     Python 2.2:   60717
+#     Python 2.3a0: 62011
+#     Python 2.3a0: 62021
+#     Python 2.3a0: 62011 (!)
+#     Python 2.4a0: 62041
+#     Python 2.4a3: 62051
+#     Python 2.4b1: 62061
+#     Python 2.5a0: 62071
+#     Python 2.5a0: 62081 (ast-branch)
+#     Python 2.5a0: 62091 (with)
+#     Python 2.5a0: 62092 (changed WITH_CLEANUP opcode)
+#     Python 2.5b3: 62101 (fix wrong code: for x, in ...)
+#     Python 2.5b3: 62111 (fix wrong code: x += yield)
+#     Python 2.5c1: 62121 (fix wrong lnotab with for loops and
+#                          storing constants that should have been removed)
+#     Python 2.5c2: 62131 (fix wrong code: for x, in ... in listcomp/genexp)
+#     Python 2.6a0: 62151 (peephole optimizations and STORE_MAP opcode)
+#     Python 2.6a1: 62161 (WITH_CLEANUP optimization)
+#     Python 2.7a0: 62171 (optimize list comprehensions/change LIST_APPEND)
+#     Python 2.7a0: 62181 (optimize conditional branches:
+#                          introduce POP_JUMP_IF_FALSE and POP_JUMP_IF_TRUE)
+#     Python 2.7a0  62191 (introduce SETUP_WITH)
+#     Python 2.7a0  62201 (introduce BUILD_SET)
+#     Python 2.7a0  62211 (introduce MAP_ADD and SET_ADD)
+#     Python 3000:   3000
+#                    3010 (removed UNARY_CONVERT)
+#                    3020 (added BUILD_SET)
+#                    3030 (added keyword-only parameters)
+#                    3040 (added signature annotations)
+#                    3050 (print becomes a function)
+#                    3060 (PEP 3115 metaclass syntax)
+#                    3061 (string literals become unicode)
+#                    3071 (PEP 3109 raise changes)
+#                    3081 (PEP 3137 make __file__ and __name__ unicode)
+#                    3091 (kill str8 interning)
+#                    3101 (merge from 2.6a0, see 62151)
+#                    3103 (__file__ points to source file)
+#     Python 3.0a4: 3111 (WITH_CLEANUP optimization).
+#     Python 3.0a5: 3131 (lexical exception stacking, including POP_EXCEPT)
+#     Python 3.1a0: 3141 (optimize list, set and dict comprehensions:
+#             change LIST_APPEND and SET_ADD, add MAP_ADD)
+#     Python 3.1a0: 3151 (optimize conditional branches:
+#             introduce POP_JUMP_IF_FALSE and POP_JUMP_IF_TRUE)
+#     Python 3.2a0: 3160 (add SETUP_WITH)
+#                   tag: cpython-32
+#     Python 3.2a1: 3170 (add DUP_TOP_TWO, remove DUP_TOPX and ROT_FOUR)
+#                   tag: cpython-32
+#     Python 3.2a2  3180 (add DELETE_DEREF)
+#     Python 3.3a0  3190 __class__ super closure changed
+#     Python 3.3a0  3200 (__qualname__ added)
+#                      3210 (added size modulo 2**32 to the pyc header)
+#     Python 3.3a1  3220 (changed PEP 380 implementation)
+#     Python 3.3a4  3230 (revert changes to implicit __class__ closure)
+#     Python 3.4a1  3250 (evaluate positional default arguments before
+#                        keyword-only defaults)
+#
+# MAGIC must change whenever the bytecode emitted by the compiler may no
+# longer be understood by older implementations of the eval loop (usually
+# due to the addition of new opcodes).
 
-"""
-_RAW_MAGIC_NUMBER = 3230 | ord('\r') << 16 | ord('\n') << 24
-_MAGIC_BYTES = bytes(_RAW_MAGIC_NUMBER >> n & 0xff for n in range(0, 25, 8))
+_MAGIC_BYTES = (3250).to_bytes(2, 'little') + b'\r\n'
+_RAW_MAGIC_NUMBER = int.from_bytes(_MAGIC_BYTES, 'little')
 
 _PYCACHE = '__pycache__'
 
@@ -508,7 +499,7 @@ def set_loader(fxn):
     """Set __loader__ on the returned module."""
     def set_loader_wrapper(self, *args, **kwargs):
         module = fxn(self, *args, **kwargs)
-        if not hasattr(module, '__loader__'):
+        if getattr(module, '__loader__', None) is None:
             module.__loader__ = self
         return module
     _wrap(set_loader_wrapper, fxn)
@@ -623,6 +614,81 @@ def _find_module_shim(self, fullname):
     return loader
 
 
+def _validate_bytecode_header(data, source_stats=None, name=None, path=None):
+    """Validate the header of the passed-in bytecode against source_stats (if
+    given) and returning the bytecode that can be compiled by compile().
+
+    All other arguments are used to enhance error reporting.
+
+    ImportError is raised when the magic number is incorrect or the bytecode is
+    found to be stale. EOFError is raised when the data is found to be
+    truncated.
+
+    """
+    exc_details = {}
+    if name is not None:
+        exc_details['name'] = name
+    else:
+        # To prevent having to make all messages have a conditional name.
+        name = '<bytecode>'
+    if path is not None:
+        exc_details['path'] = path
+    magic = data[:4]
+    raw_timestamp = data[4:8]
+    raw_size = data[8:12]
+    if magic != _MAGIC_BYTES:
+        message = 'bad magic number in {!r}: {!r}'.format(name, magic)
+        _verbose_message(message)
+        raise ImportError(message, **exc_details)
+    elif len(raw_timestamp) != 4:
+        message = 'incomplete timestamp in {!r}'.format(name)
+        _verbose_message(message)
+        raise EOFError(message)
+    elif len(raw_size) != 4:
+        message = 'incomplete size in {!r}'.format(name)
+        _verbose_message(message)
+        raise EOFError(message)
+    if source_stats is not None:
+        try:
+            source_mtime = int(source_stats['mtime'])
+        except KeyError:
+            pass
+        else:
+            if _r_long(raw_timestamp) != source_mtime:
+                message = 'bytecode is stale for {!r}'.format(name)
+                _verbose_message(message)
+                raise ImportError(message, **exc_details)
+        try:
+            source_size = source_stats['size'] & 0xFFFFFFFF
+        except KeyError:
+            pass
+        else:
+            if _r_long(raw_size) != source_size:
+                raise ImportError("bytecode is stale for {!r}".format(name),
+                                  **exc_details)
+    return data[12:]
+
+
+def _compile_bytecode(data, name=None, bytecode_path=None, source_path=None):
+    """Compile bytecode as returned by _validate_bytecode_header()."""
+    code = marshal.loads(data)
+    if isinstance(code, _code_type):
+        _verbose_message('code object from {!r}', bytecode_path)
+        if source_path is not None:
+            _imp._fix_co_filename(code, source_path)
+        return code
+    else:
+        raise ImportError("Non-code object in {!r}".format(bytecode_path),
+                          name=name, path=bytecode_path)
+
+def _code_to_bytecode(code, mtime=0, source_size=0):
+    """Compile a code object into bytecode for writing out to a byte-compiled
+    file."""
+    data = bytearray(_MAGIC_BYTES)
+    data.extend(_w_long(mtime))
+    data.extend(_w_long(source_size))
+    data.extend(marshal.dumps(code))
+    return data
 
 
 # Loaders #####################################################################
@@ -755,7 +821,7 @@ class WindowsRegistryFinder:
     def _open_registry(cls, key):
         try:
             return _winreg.OpenKey(_winreg.HKEY_CURRENT_USER, key)
-        except WindowsError:
+        except OSError:
             return _winreg.OpenKey(_winreg.HKEY_LOCAL_MACHINE, key)
 
     @classmethod
@@ -769,7 +835,7 @@ class WindowsRegistryFinder:
         try:
             with cls._open_registry(key) as hkey:
                 filepath = _winreg.QueryValue(hkey, "")
-        except WindowsError:
+        except OSError:
             return None
         return filepath
 
@@ -801,52 +867,6 @@ class _LoaderBasics:
         tail_name = fullname.rpartition('.')[2]
         return filename_base == '__init__' and tail_name != '__init__'
 
-    def _bytes_from_bytecode(self, fullname, data, bytecode_path, source_stats):
-        """Return the marshalled bytes from bytecode, verifying the magic
-        number, timestamp and source size along the way.
-
-        If source_stats is None then skip the timestamp check.
-
-        """
-        magic = data[:4]
-        raw_timestamp = data[4:8]
-        raw_size = data[8:12]
-        if magic != _MAGIC_BYTES:
-            msg = 'bad magic number in {!r}: {!r}'.format(fullname, magic)
-            _verbose_message(msg)
-            raise ImportError(msg, name=fullname, path=bytecode_path)
-        elif len(raw_timestamp) != 4:
-            message = 'bad timestamp in {}'.format(fullname)
-            _verbose_message(message)
-            raise EOFError(message)
-        elif len(raw_size) != 4:
-            message = 'bad size in {}'.format(fullname)
-            _verbose_message(message)
-            raise EOFError(message)
-        if source_stats is not None:
-            try:
-                source_mtime = int(source_stats['mtime'])
-            except KeyError:
-                pass
-            else:
-                if _r_long(raw_timestamp) != source_mtime:
-                    message = 'bytecode is stale for {}'.format(fullname)
-                    _verbose_message(message)
-                    raise ImportError(message, name=fullname,
-                                      path=bytecode_path)
-            try:
-                source_size = source_stats['size'] & 0xFFFFFFFF
-            except KeyError:
-                pass
-            else:
-                if _r_long(raw_size) != source_size:
-                    raise ImportError(
-                        "bytecode is stale for {}".format(fullname),
-                        name=fullname, path=bytecode_path)
-        # Can't return the code object as errors from marshal loading need to
-        # propagate even when source is available.
-        return data[12:]
-
     @module_for_loader
     def _load_module(self, module, *, sourceless=False):
         """Helper for load_module able to handle either source or sourceless
@@ -861,12 +881,9 @@ class _LoaderBasics:
                 module.__cached__ = module.__file__
         else:
             module.__cached__ = module.__file__
-        module.__package__ = name
         if self.is_package(name):
             module.__path__ = [_path_split(module.__file__)[0]]
-        else:
-            module.__package__ = module.__package__.rpartition('.')[0]
-        module.__loader__ = self
+        # __package__ and __loader set by @module_for_loader.
         _call_with_frames_removed(exec, code_object, module.__dict__)
         return module
 
@@ -916,7 +933,7 @@ class SourceLoader(_LoaderBasics):
         path = self.get_filename(fullname)
         try:
             source_bytes = self.get_data(path)
-        except IOError as exc:
+        except OSError as exc:
             raise ImportError("source not available through get_data()",
                               name=fullname) from exc
         readsource = _io.BytesIO(source_bytes).readline
@@ -932,6 +949,14 @@ class SourceLoader(_LoaderBasics):
             raise ImportError("Failed to decode source file",
                               name=fullname) from exc
 
+    def source_to_code(self, data, path, *, _optimize=-1):
+        """Return the code object compiled from source.
+
+        The 'data' argument can be any object type that compile() supports.
+        """
+        return _call_with_frames_removed(compile, data, path, 'exec',
+                                        dont_inherit=True, optimize=_optimize)
+
     def get_code(self, fullname):
         """Concrete implementation of InspectLoader.get_code.
 
@@ -954,39 +979,28 @@ class SourceLoader(_LoaderBasics):
                 source_mtime = int(st['mtime'])
                 try:
                     data = self.get_data(bytecode_path)
-                except IOError:
+                except OSError:
                     pass
                 else:
                     try:
-                        bytes_data = self._bytes_from_bytecode(fullname, data,
-                                                               bytecode_path,
-                                                               st)
+                        bytes_data = _validate_bytecode_header(data,
+                                source_stats=st, name=fullname,
+                                path=bytecode_path)
                     except (ImportError, EOFError):
                         pass
                     else:
                         _verbose_message('{} matches {}', bytecode_path,
                                         source_path)
-                        found = marshal.loads(bytes_data)
-                        if isinstance(found, _code_type):
-                            _imp._fix_co_filename(found, source_path)
-                            _verbose_message('code object from {}',
-                                            bytecode_path)
-                            return found
-                        else:
-                            msg = "Non-code object in {}"
-                            raise ImportError(msg.format(bytecode_path),
-                                              name=fullname, path=bytecode_path)
+                        return _compile_bytecode(bytes_data, name=fullname,
+                                                 bytecode_path=bytecode_path,
+                                                 source_path=source_path)
         source_bytes = self.get_data(source_path)
-        code_object = _call_with_frames_removed(compile,
-                          source_bytes, source_path, 'exec',
-                          dont_inherit=True)
+        code_object = self.source_to_code(source_bytes, source_path)
         _verbose_message('code object from {}', source_path)
         if (not sys.dont_write_bytecode and bytecode_path is not None and
-            source_mtime is not None):
-            data = bytearray(_MAGIC_BYTES)
-            data.extend(_w_long(source_mtime))
-            data.extend(_w_long(len(source_bytes)))
-            data.extend(marshal.dumps(code_object))
+                source_mtime is not None):
+            data = _code_to_bytecode(code_object, source_mtime,
+                    len(source_bytes))
             try:
                 self._cache_bytecode(source_path, bytecode_path, data)
                 _verbose_message('wrote {!r}', bytecode_path)
@@ -1093,14 +1107,8 @@ class SourcelessFileLoader(FileLoader, _LoaderBasics):
     def get_code(self, fullname):
         path = self.get_filename(fullname)
         data = self.get_data(path)
-        bytes_data = self._bytes_from_bytecode(fullname, data, path, None)
-        found = marshal.loads(bytes_data)
-        if isinstance(found, _code_type):
-            _verbose_message('code object from {!r}', path)
-            return found
-        else:
-            raise ImportError("Non-code object in {}".format(path),
-                              name=fullname, path=path)
+        bytes_data = _validate_bytecode_header(data, name=fullname, path=path)
+        return _compile_bytecode(bytes_data, name=fullname, bytecode_path=path)
 
     def get_source(self, fullname):
         """Return None as there is no source code."""
@@ -1422,7 +1430,7 @@ class FileFinder:
                 lower_suffix_contents.add(new_name)
             self._path_cache = lower_suffix_contents
         if sys.platform.startswith(_CASE_INSENSITIVE_PLATFORMS):
-            self._relaxed_path_cache = set(fn.lower() for fn in contents)
+            self._relaxed_path_cache = {fn.lower() for fn in contents}
 
     @classmethod
     def path_hook(cls, *loader_details):
@@ -1443,7 +1451,7 @@ class FileFinder:
         return path_hook_for_FileFinder
 
     def __repr__(self):
-        return "FileFinder(%r)" % (self.path,)
+        return "FileFinder({!r})".format(self.path)
 
 
 # Import itself ###############################################################
@@ -1548,7 +1556,7 @@ def _find_and_load_unlocked(name, import_):
         except AttributeError:
             pass
     # Set loader if need be.
-    if not hasattr(module, '__loader__'):
+    if getattr(module, '__loader__', None) is None:
         try:
             module.__loader__ = loader
         except AttributeError:
@@ -1723,7 +1731,7 @@ def _setup(sys_module, _imp_module):
             builtin_module = sys.modules[builtin_name]
         setattr(self_module, builtin_name, builtin_module)
 
-    os_details = ('posix', ['/']), ('nt', ['\\', '/']), ('os2', ['\\', '/'])
+    os_details = ('posix', ['/']), ('nt', ['\\', '/'])
     for builtin_os, path_separators in os_details:
         # Assumption made in _path_join()
         assert all(len(sep) == 1 for sep in path_separators)
@@ -1734,9 +1742,6 @@ def _setup(sys_module, _imp_module):
         else:
             try:
                 os_module = BuiltinImporter.load_module(builtin_os)
-                # TODO: rip out os2 code after 3.3 is released as per PEP 11
-                if builtin_os == 'os2' and 'EMX GCC' in sys.version:
-                    path_sep = path_separators[1]
                 break
             except ImportError:
                 continue
@@ -1758,7 +1763,7 @@ def _setup(sys_module, _imp_module):
     setattr(self_module, '_thread', thread_module)
     setattr(self_module, '_weakref', weakref_module)
     setattr(self_module, 'path_sep', path_sep)
-    setattr(self_module, 'path_separators', set(path_separators))
+    setattr(self_module, 'path_separators', ''.join(path_separators))
     # Constants
     setattr(self_module, '_relax_case', _make_relax_case())
     EXTENSION_SUFFIXES.extend(_imp.extension_suffixes())
diff --git a/Lib/importlib/abc.py b/Lib/importlib/abc.py
index 387567a450..11e45f4a91 100644
--- a/Lib/importlib/abc.py
+++ b/Lib/importlib/abc.py
@@ -225,180 +225,3 @@ class SourceLoader(_bootstrap.SourceLoader, ResourceLoader, ExecutionLoader):
         raise NotImplementedError
 
 _register(SourceLoader, machinery.SourceFileLoader)
-
-class PyLoader(SourceLoader):
-
-    """Implement the deprecated PyLoader ABC in terms of SourceLoader.
-
-    This class has been deprecated! It is slated for removal in Python 3.4.
-    If compatibility with Python 3.1 is not needed then implement the
-    SourceLoader ABC instead of this class. If Python 3.1 compatibility is
-    needed, then use the following idiom to have a single class that is
-    compatible with Python 3.1 onwards::
-
-        try:
-            from importlib.abc import SourceLoader
-        except ImportError:
-            from importlib.abc import PyLoader as SourceLoader
-
-
-        class CustomLoader(SourceLoader):
-            def get_filename(self, fullname):
-                # Implement ...
-
-            def source_path(self, fullname):
-                '''Implement source_path in terms of get_filename.'''
-                try:
-                    return self.get_filename(fullname)
-                except ImportError:
-                    return None
-
-            def is_package(self, fullname):
-                filename = os.path.basename(self.get_filename(fullname))
-                return os.path.splitext(filename)[0] == '__init__'
-
-    """
-
-    @abc.abstractmethod
-    def is_package(self, fullname):
-        raise NotImplementedError
-
-    @abc.abstractmethod
-    def source_path(self, fullname):
-        """Abstract method.  Accepts a str module name and returns the path to
-        the source code for the module."""
-        raise NotImplementedError
-
-    def get_filename(self, fullname):
-        """Implement get_filename in terms of source_path.
-
-        As get_filename should only return a source file path there is no
-        chance of the path not existing but loading still being possible, so
-        ImportError should propagate instead of being turned into returning
-        None.
-
-        """
-        warnings.warn("importlib.abc.PyLoader is deprecated and is "
-                            "slated for removal in Python 3.4; "
-                            "use SourceLoader instead. "
-                            "See the importlib documentation on how to be "
-                            "compatible with Python 3.1 onwards.",
-                        DeprecationWarning)
-        path = self.source_path(fullname)
-        if path is None:
-            raise ImportError(name=fullname)
-        else:
-            return path
-
-
-class PyPycLoader(PyLoader):
-
-    """Abstract base class to assist in loading source and bytecode by
-    requiring only back-end storage methods to be implemented.
-
-    This class has been deprecated! Removal is slated for Python 3.4. Implement
-    the SourceLoader ABC instead. If Python 3.1 compatibility is needed, see
-    PyLoader.
-
-    The methods get_code, get_source, and load_module are implemented for the
-    user.
-
-    """
-
-    def get_filename(self, fullname):
-        """Return the source or bytecode file path."""
-        path = self.source_path(fullname)
-        if path is not None:
-            return path
-        path = self.bytecode_path(fullname)
-        if path is not None:
-            return path
-        raise ImportError("no source or bytecode path available for "
-                            "{0!r}".format(fullname), name=fullname)
-
-    def get_code(self, fullname):
-        """Get a code object from source or bytecode."""
-        warnings.warn("importlib.abc.PyPycLoader is deprecated and slated for "
-                            "removal in Python 3.4; use SourceLoader instead. "
-                            "If Python 3.1 compatibility is required, see the "
-                            "latest documentation for PyLoader.",
-                        DeprecationWarning)
-        source_timestamp = self.source_mtime(fullname)
-        # Try to use bytecode if it is available.
-        bytecode_path = self.bytecode_path(fullname)
-        if bytecode_path:
-            data = self.get_data(bytecode_path)
-            try:
-                magic = data[:4]
-                if len(magic) < 4:
-                    raise ImportError(
-                        "bad magic number in {}".format(fullname),
-                        name=fullname, path=bytecode_path)
-                raw_timestamp = data[4:8]
-                if len(raw_timestamp) < 4:
-                    raise EOFError("bad timestamp in {}".format(fullname))
-                pyc_timestamp = _bootstrap._r_long(raw_timestamp)
-                raw_source_size = data[8:12]
-                if len(raw_source_size) != 4:
-                    raise EOFError("bad file size in {}".format(fullname))
-                # Source size is unused as the ABC does not provide a way to
-                # get the size of the source ahead of reading it.
-                bytecode = data[12:]
-                # Verify that the magic number is valid.
-                if imp.get_magic() != magic:
-                    raise ImportError(
-                        "bad magic number in {}".format(fullname),
-                        name=fullname, path=bytecode_path)
-                # Verify that the bytecode is not stale (only matters when
-                # there is source to fall back on.
-                if source_timestamp:
-                    if pyc_timestamp < source_timestamp:
-                        raise ImportError("bytecode is stale", name=fullname,
-                                          path=bytecode_path)
-            except (ImportError, EOFError):
-                # If source is available give it a shot.
-                if source_timestamp is not None:
-                    pass
-                else:
-                    raise
-            else:
-                # Bytecode seems fine, so try to use it.
-                return marshal.loads(bytecode)
-        elif source_timestamp is None:
-            raise ImportError("no source or bytecode available to create code "
-                              "object for {0!r}".format(fullname),
-                              name=fullname)
-        # Use the source.
-        source_path = self.source_path(fullname)
-        if source_path is None:
-            message = "a source path must exist to load {0}".format(fullname)
-            raise ImportError(message, name=fullname)
-        source = self.get_data(source_path)
-        code_object = compile(source, source_path, 'exec', dont_inherit=True)
-        # Generate bytecode and write it out.
-        if not sys.dont_write_bytecode:
-            data = bytearray(imp.get_magic())
-            data.extend(_bootstrap._w_long(source_timestamp))
-            data.extend(_bootstrap._w_long(len(source) & 0xFFFFFFFF))
-            data.extend(marshal.dumps(code_object))
-            self.write_bytecode(fullname, data)
-        return code_object
-
-    @abc.abstractmethod
-    def source_mtime(self, fullname):
-        """Abstract method. Accepts a str filename and returns an int
-        modification time for the source of the module."""
-        raise NotImplementedError
-
-    @abc.abstractmethod
-    def bytecode_path(self, fullname):
-        """Abstract method. Accepts a str filename and returns the str pathname
-        to the bytecode for the module."""
-        raise NotImplementedError
-
-    @abc.abstractmethod
-    def write_bytecode(self, fullname, bytecode):
-        """Abstract method.  Accepts a str filename and bytes object
-        representing the bytecode for the module.  Returns a boolean
-        representing whether the bytecode was written or not."""
-        raise NotImplementedError