def install_hooks():
"""
This function installs the future.standard_library import hook into
sys.meta_path.
"""
if PY3:
return
install_aliases()
flog.debug('sys.meta_path was: {0}'.format(sys.meta_path))
flog.debug('Installing hooks ...')
# Add it unless it's there already
newhook = RenameImport(RENAMES)
if not detect_hooks():
sys.meta_path.append(newhook)
flog.debug('sys.meta_path is now: {0}'.format(sys.meta_path))
python类PY3的实例源码
def remove_hooks(scrub_sys_modules=False):
"""
This function removes the import hook from sys.meta_path.
"""
if PY3:
return
flog.debug('Uninstalling hooks ...')
# Loop backwards, so deleting items keeps the ordering:
for i, hook in list(enumerate(sys.meta_path))[::-1]:
if hasattr(hook, 'RENAMER'):
del sys.meta_path[i]
# Explicit is better than implicit. In the future the interface should
# probably change so that scrubbing the import hooks requires a separate
# function call. Left as is for now for backward compatibility with
# v0.11.x.
if scrub_sys_modules:
scrub_future_sys_modules()
def scrub_py2_sys_modules():
"""
Removes any Python 2 standard library modules from ``sys.modules`` that
would interfere with Py3-style imports using import hooks. Examples are
modules with the same names (like urllib or email).
(Note that currently import hooks are disabled for modules like these
with ambiguous names anyway ...)
"""
if PY3:
return {}
scrubbed = {}
for modulename in REPLACED_MODULES & set(RENAMES.keys()):
if not modulename in sys.modules:
continue
module = sys.modules[modulename]
if is_py2_stdlib_module(module):
flog.debug('Deleting (Py2) {} from sys.modules'.format(modulename))
scrubbed[modulename] = sys.modules[modulename]
del sys.modules[modulename]
return scrubbed
def install_hooks():
"""
This function installs the future.standard_library import hook into
sys.meta_path.
"""
if PY3:
return
install_aliases()
flog.debug('sys.meta_path was: {0}'.format(sys.meta_path))
flog.debug('Installing hooks ...')
# Add it unless it's there already
newhook = RenameImport(RENAMES)
if not detect_hooks():
sys.meta_path.append(newhook)
flog.debug('sys.meta_path is now: {0}'.format(sys.meta_path))
def remove_hooks(scrub_sys_modules=False):
"""
This function removes the import hook from sys.meta_path.
"""
if PY3:
return
flog.debug('Uninstalling hooks ...')
# Loop backwards, so deleting items keeps the ordering:
for i, hook in list(enumerate(sys.meta_path))[::-1]:
if hasattr(hook, 'RENAMER'):
del sys.meta_path[i]
# Explicit is better than implicit. In the future the interface should
# probably change so that scrubbing the import hooks requires a separate
# function call. Left as is for now for backward compatibility with
# v0.11.x.
if scrub_sys_modules:
scrub_future_sys_modules()
def scrub_py2_sys_modules():
"""
Removes any Python 2 standard library modules from ``sys.modules`` that
would interfere with Py3-style imports using import hooks. Examples are
modules with the same names (like urllib or email).
(Note that currently import hooks are disabled for modules like these
with ambiguous names anyway ...)
"""
if PY3:
return {}
scrubbed = {}
for modulename in REPLACED_MODULES & set(RENAMES.keys()):
if not modulename in sys.modules:
continue
module = sys.modules[modulename]
if is_py2_stdlib_module(module):
flog.debug('Deleting (Py2) {} from sys.modules'.format(modulename))
scrubbed[modulename] = sys.modules[modulename]
del sys.modules[modulename]
return scrubbed
def install_hooks():
"""
This function installs the future.standard_library import hook into
sys.meta_path.
"""
if PY3:
return
install_aliases()
flog.debug('sys.meta_path was: {0}'.format(sys.meta_path))
flog.debug('Installing hooks ...')
# Add it unless it's there already
newhook = RenameImport(RENAMES)
if not detect_hooks():
sys.meta_path.append(newhook)
flog.debug('sys.meta_path is now: {0}'.format(sys.meta_path))
def remove_hooks(scrub_sys_modules=False):
"""
This function removes the import hook from sys.meta_path.
"""
if PY3:
return
flog.debug('Uninstalling hooks ...')
# Loop backwards, so deleting items keeps the ordering:
for i, hook in list(enumerate(sys.meta_path))[::-1]:
if hasattr(hook, 'RENAMER'):
del sys.meta_path[i]
# Explicit is better than implicit. In the future the interface should
# probably change so that scrubbing the import hooks requires a separate
# function call. Left as is for now for backward compatibility with
# v0.11.x.
if scrub_sys_modules:
scrub_future_sys_modules()
def expectedFailurePY3(func):
if not PY3:
return func
return unittest.expectedFailure(func)
def is_py2_stdlib_module(m):
"""
Tries to infer whether the module m is from the Python 2 standard library.
This may not be reliable on all systems.
"""
if PY3:
return False
if not 'stdlib_path' in is_py2_stdlib_module.__dict__:
stdlib_files = [contextlib.__file__, os.__file__, copy.__file__]
stdlib_paths = [os.path.split(f)[0] for f in stdlib_files]
if not len(set(stdlib_paths)) == 1:
# This seems to happen on travis-ci.org. Very strange. We'll try to
# ignore it.
flog.warn('Multiple locations found for the Python standard '
'library: %s' % stdlib_paths)
# Choose the first one arbitrarily
is_py2_stdlib_module.stdlib_path = stdlib_paths[0]
if m.__name__ in sys.builtin_module_names:
return True
if hasattr(m, '__file__'):
modpath = os.path.split(m.__file__)
if (modpath[0].startswith(is_py2_stdlib_module.stdlib_path) and
'site-packages' not in modpath[0]):
return True
return False
def from_import(module_name, *symbol_names, **kwargs):
"""
Example use:
>>> HTTPConnection = from_import('http.client', 'HTTPConnection')
>>> HTTPServer = from_import('http.server', 'HTTPServer')
>>> urlopen, urlparse = from_import('urllib.request', 'urlopen', 'urlparse')
Equivalent to this on Py3:
>>> from module_name import symbol_names[0], symbol_names[1], ...
and this on Py2:
>>> from future.moves.module_name import symbol_names[0], ...
or:
>>> from future.backports.module_name import symbol_names[0], ...
except that it also handles dotted module names such as ``http.client``.
"""
if PY3:
return __import__(module_name)
else:
if 'backport' in kwargs and bool(kwargs['backport']):
prefix = 'future.backports'
else:
prefix = 'future.moves'
parts = prefix.split('.') + module_name.split('.')
module = importlib.import_module(prefix + '.' + module_name)
output = [getattr(module, name) for name in symbol_names]
if len(output) == 1:
return output[0]
else:
return output
def u(text):
if utils.PY3:
return text
else:
return text.decode('unicode_escape')
def b(data):
if utils.PY3:
return data.encode('latin1')
else:
return data
def replace_surrogate_encode(mystring):
"""
Returns a (unicode) string, not the more logical bytes, because the codecs
register_error functionality expects this.
"""
decoded = []
for ch in mystring:
# if utils.PY3:
# code = ch
# else:
code = ord(ch)
# The following magic comes from Py3.3's Python/codecs.c file:
if not 0xD800 <= code <= 0xDCFF:
# Not a surrogate. Fail with the original exception.
raise exc
# mybytes = [0xe0 | (code >> 12),
# 0x80 | ((code >> 6) & 0x3f),
# 0x80 | (code & 0x3f)]
# Is this a good idea?
if 0xDC00 <= code <= 0xDC7F:
decoded.append(_unichr(code - 0xDC00))
elif code <= 0xDCFF:
decoded.append(_unichr(code - 0xDC00))
else:
raise NotASurrogateError
return str().join(decoded)
def register_surrogateescape():
"""
Registers the surrogateescape error handler on Python 2 (only)
"""
if utils.PY3:
return
try:
codecs.lookup_error(FS_ERRORS)
except LookupError:
codecs.register_error(FS_ERRORS, surrogateescape_handler)
def __init__(self, _factory=message.Message, **_3to2kwargs):
if 'policy' in _3to2kwargs: policy = _3to2kwargs['policy']; del _3to2kwargs['policy']
else: policy = compat32
"""_factory is called with no arguments to create a new message obj
The policy keyword specifies a policy object that controls a number of
aspects of the parser's operation. The default policy maintains
backward compatibility.
"""
self._factory = _factory
self.policy = policy
try:
_factory(policy=self.policy)
self._factory_kwds = lambda: {'policy': self.policy}
except TypeError:
# Assume this is an old-style factory
self._factory_kwds = lambda: {}
self._input = BufferedSubFile()
self._msgstack = []
if PY3:
self._parse = self._parsegen().__next__
else:
self._parse = self._parsegen().next
self._cur = None
self._last = None
self._headersonly = False
# Non-public interface for supporting Parser's headersonly flag
def test_isinstance_long(self):
"""
Py2's long doesn't inherit from int!
"""
self.assertTrue(isinstance(10**100, int))
self.assertTrue(isinstance(int(2**64), int))
if not PY3:
self.assertTrue(isinstance(long(1), int))
# Note: the following is a SyntaxError on Py3:
# self.assertTrue(isinstance(1L, int))
def test_bad_status_repr(self):
exc = client.BadStatusLine('')
if not utils.PY3:
self.assertEqual(repr(exc), '''BadStatusLine("u\'\'",)''')
else:
self.assertEqual(repr(exc), '''BadStatusLine("\'\'",)''')
def test_namespace_pollution_locals(self):
if utils.PY3:
self.assertEqual(len(new_locals), 0,
'namespace pollution: {0}'.format(new_locals))
else:
pass # maybe check that no new symbols are introduced
def test_namespace_pollution_globals(self):
if utils.PY3:
self.assertEqual(len(new_globals), 0,
'namespace pollution: {0}'.format(new_globals))
else:
pass # maybe check that no new symbols are introduced
