Rename sys to _sys and proxy it.

Lib/_collections_abc.py

@@ -7,7 +7,7 @@
 """
 
 from abc import ABCMeta, abstractmethod
-import sys
+import _sys as sys  # We use the low-level module during interpreter init.
 
 __all__ = ["Awaitable", "Coroutine",
            "AsyncIterable", "AsyncIterator", "AsyncGenerator",

Lib/_compat_pickle.py

@@ -57,7 +57,7 @@
 NAME_MAPPING = {
     ('__builtin__', 'xrange'):     ('builtins', 'range'),
     ('__builtin__', 'reduce'):     ('functools', 'reduce'),
-    ('__builtin__', 'intern'):     ('sys', 'intern'),
+    ('__builtin__', 'intern'):     ('_sys', 'intern'),
     ('__builtin__', 'unichr'):     ('builtins', 'chr'),
     ('__builtin__', 'unicode'):    ('builtins', 'str'),
     ('__builtin__', 'long'):       ('builtins', 'int'),

Lib/_sitebuiltins.py

@@ -8,7 +8,7 @@
 # Note this means this module should also avoid keep things alive in its
 # globals.
 
-import sys
+import _sys as sys  # We use the low-level module during interpreter init.
 
 class Quitter(object):
     def __init__(self, name, eof):

Lib/codecs.py

@@ -8,7 +8,7 @@
 """
 
 import builtins
-import sys
+import _sys as sys  # We use the low-level module during interpreter init.
 
 ### Registry and builtin stateless codec functions
 

Lib/collections/__init__.py

@@ -25,7 +25,7 @@
 
 from operator import itemgetter as _itemgetter, eq as _eq
 from keyword import iskeyword as _iskeyword
-import sys as _sys
+import _sys  # We use the low-level module during interpreter init.
 import heapq as _heapq
 from _weakref import proxy as _proxy
 from itertools import repeat as _repeat, chain as _chain, starmap as _starmap

Lib/contextlib.py

@@ -1,6 +1,6 @@
 """Utilities for with-statement contexts.  See PEP 343."""
 import abc
-import sys
+import _sys as sys
 import _collections_abc
 from collections import deque
 from functools import wraps

Lib/doctest.py

@@ -209,7 +209,7 @@ def _normalize_module(module, depth=2):
     elif module is None:
         return sys.modules[sys._getframe(depth).f_globals['__name__']]
     else:
-        raise TypeError("Expected a module, string, or None")
+        raise TypeError("Expected a module, string, or None, got {}".format(type(module)))
 
 def _load_testfile(filename, package, module_relative, encoding):
     if module_relative:

Lib/encodings/__init__.py

@@ -29,7 +29,7 @@
 """#"
 
 import codecs
-import sys
+import _sys as sys
 from . import aliases
 
 _cache = {}

Lib/enum.py

@@ -1,4 +1,4 @@
-import sys
+import _sys as sys
 from types import MappingProxyType, DynamicClassAttribute
 from functools import reduce
 from operator import or_ as _or_

Lib/importlib/__init__.py

@@ -10,7 +10,7 @@
 # of a fully initialised version (either the frozen one or the one
 # initialised below if the frozen one is not available).
 import _imp  # Just the builtin component, NOT the full Python module
-import sys
+import _sys as sys
 
 try:
     import _frozen_importlib as _bootstrap

Lib/importlib/_bootstrap_external.py

@@ -968,8 +968,8 @@ def _find_parent_path_names(self):
         """Returns a tuple of (parent-module-name, parent-path-attr-name)"""
         parent, dot, me = self._name.rpartition('.')
         if dot == '':
-            # This is a top-level module. sys.path contains the parent path.
-            return 'sys', 'path'
+            # This is a top-level module. _sys.path contains the parent path.
+            return '_sys', 'path'
         # Not a top-level module. parent-module.__path__ contains the
         #  parent path.
         return parent, '__path__'

Lib/importlib/util.py

@@ -12,7 +12,7 @@
 
 from contextlib import contextmanager
 import functools
-import sys
+import _sys as sys
 import types
 import warnings
 

Lib/locale.py

@@ -10,7 +10,7 @@
 
 """
 
-import sys
+import _sys as sys
 import encodings
 import encodings.aliases
 import re

Lib/ntpath.py

@@ -6,7 +6,7 @@
 """
 
 import os
-import sys
+import _sys as sys  # We use the low-level module during interpreter init.
 import stat
 import genericpath
 from genericpath import *

Lib/optparse.py

@@ -73,7 +73,8 @@
 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 """
 
-import sys, os
+import os
+import _sys as sys
 import textwrap
 
 def _repr(self):

Lib/os.py

@@ -23,7 +23,8 @@
 
 #'
 import abc
-import sys, errno
+import errno
+import _sys as sys  # We use the low-level module during interpreter init.
 import stat as st
 
 _names = sys.builtin_module_names

Lib/pkgutil.py

@@ -7,7 +7,7 @@
 import importlib.machinery
 import os
 import os.path
-import sys
+import _sys as sys
 from types import ModuleType
 import warnings
 

Lib/posixpath.py

@@ -11,7 +11,7 @@
 """
 
 import os
-import sys
+import _sys as sys  # We use the low-level module during interpreter init.
 import stat
 import genericpath
 from genericpath import *

Lib/pydoc.py

@@ -410,7 +410,7 @@ def getdocloc(self, object,
         basedir = os.path.normcase(basedir)
         if (isinstance(object, type(os)) and
             (object.__name__ in ('errno', 'exceptions', 'gc', 'imp',
-                                 'marshal', 'posix', 'signal', 'sys',
+                                 'marshal', 'posix', 'signal', '_sys',
                                  '_thread', 'zipimport') or
              (file.startswith(basedir) and
               not file.startswith(os.path.join(basedir, 'site-packages')))) and

Lib/runpy.py

@@ -10,7 +10,7 @@
 #    to implement PEP 338 (Executing Modules as Scripts)
 
 
-import sys
+import _sys as sys  # the low-level module
 import importlib.machinery # importlib first so we can test #15386 via -m
 import importlib.util
 import types

Lib/site.py

@@ -69,7 +69,7 @@
 ImportError exception, it is silently ignored.
 """
 
-import sys
+import _sys as sys  # We use the low-level module during interpreter init.
 import os
 import builtins
 import _sitebuiltins

Lib/sys.py

@@ -0,0 +1,51 @@
+"""This module provides access to some objects used or maintained by the
+interpreter and to functions that interact strongly with the interpreter.
+
+This is a wrapper around the low-level _sys module.
+"""
+
+import _sys
+
+
+MODULE_ATTRS = [
+        "__name__",
+        "__doc__",
+        "__loader__",
+        "__spec__",
+        "__package__",
+        # not in _sys:
+        "__file__",
+        "__cached__",
+        "__builtins__",
+        ]
+
+
+# For now we strictly proxy _sys.
+
+class SysModule(type(_sys)):
+
+    # XXX What about cases of "moduletype = type(sys)"?
+
+    def __init__(self, name, *, _ns=None):
+        super().__init__(name)
+
+        if _ns is not None:
+            for attr in MODULE_ATTRS:
+                object.__setattr__(self, name, _ns[attr])
+
+    def __dir__(self):
+        return sorted(dir(_sys) + MODULE_ATTRS)
+
+    def __getattr__(self, name):
+        return getattr(_sys, name)
+
+    def __setattr__(self, name, value):
+        # XXX Only wrap existing attrs?
+        setattr(_sys, name, value)
+
+    def __delattr__(self, name):
+        # XXX Only wrap existing attrs?
+        delattr(_sys, name)
+
+
+_sys.modules[__name__] = SysModule(__name__, _ns=vars())

Lib/sysconfig.py

@@ -1,7 +1,7 @@
 """Access to Python's configuration information."""
 
 import os
-import sys
+import _sys as sys  # We use the low-level module during interpreter init.
 from os.path import pardir, realpath
 
 __all__ = [

Lib/test/support/__init__.py

@@ -22,7 +22,7 @@
 import stat
 import struct
 import subprocess
-import sys
+import _sys as sys
 import sysconfig
 import tempfile
 import _thread

Lib/test/support/script_helper.py

@@ -3,7 +3,7 @@
 
 import collections
 import importlib
-import sys
+import _sys as sys
 import os
 import os.path
 import subprocess