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Python

6 years ago
"""Utilities for writing code that runs on Python 2 and 3"""
# Copyright (c) 2010-2012 Benjamin Peterson
#
# Permission is hereby granted, free of charge, to any person obtaining a copy of
# this software and associated documentation files (the "Software"), to deal in
# the Software without restriction, including without limitation the rights to
# use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
# the Software, and to permit persons to whom the Software is furnished to do so,
# subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
# FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
# COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
# IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
import operator
import sys
import types
__author__ = "Benjamin Peterson <benjamin@python.org>"
__version__ = "1.2.0"
# True if we are running on Python 3.
PY3 = sys.version_info[0] == 3
if PY3:
string_types = str,
integer_types = int,
class_types = type,
text_type = str
binary_type = bytes
MAXSIZE = sys.maxsize
else:
string_types = basestring,
integer_types = (int, long)
class_types = (type, types.ClassType)
text_type = unicode
binary_type = str
if sys.platform.startswith("java"):
# Jython always uses 32 bits.
MAXSIZE = int((1 << 31) - 1)
else:
# It's possible to have sizeof(long) != sizeof(Py_ssize_t).
class X(object):
def __len__(self):
return 1 << 31
try:
len(X())
except OverflowError:
# 32-bit
MAXSIZE = int((1 << 31) - 1)
else:
# 64-bit
MAXSIZE = int((1 << 63) - 1)
del X
def _add_doc(func, doc):
"""Add documentation to a function."""
func.__doc__ = doc
def _import_module(name):
"""Import module, returning the module after the last dot."""
__import__(name)
return sys.modules[name]
# Replacement for lazy loading stuff in upstream six. See gh-2764
if PY3:
import builtins
import functools
reduce = functools.reduce
zip = builtins.zip
xrange = builtins.range
else:
import __builtin__
import itertools
builtins = __builtin__
reduce = __builtin__.reduce
zip = itertools.izip
xrange = __builtin__.xrange
if PY3:
_meth_func = "__func__"
_meth_self = "__self__"
_func_code = "__code__"
_func_defaults = "__defaults__"
_iterkeys = "keys"
_itervalues = "values"
_iteritems = "items"
else:
_meth_func = "im_func"
_meth_self = "im_self"
_func_code = "func_code"
_func_defaults = "func_defaults"
_iterkeys = "iterkeys"
_itervalues = "itervalues"
_iteritems = "iteritems"
try:
advance_iterator = next
except NameError:
def advance_iterator(it):
return it.next()
next = advance_iterator
if PY3:
def get_unbound_function(unbound):
return unbound
Iterator = object
def callable(obj):
return any("__call__" in klass.__dict__ for klass in type(obj).__mro__)
else:
def get_unbound_function(unbound):
return unbound.im_func
class Iterator(object):
def next(self):
return type(self).__next__(self)
callable = callable
_add_doc(get_unbound_function,
"""Get the function out of a possibly unbound function""")
get_method_function = operator.attrgetter(_meth_func)
get_method_self = operator.attrgetter(_meth_self)
get_function_code = operator.attrgetter(_func_code)
get_function_defaults = operator.attrgetter(_func_defaults)
def iterkeys(d):
"""Return an iterator over the keys of a dictionary."""
return iter(getattr(d, _iterkeys)())
def itervalues(d):
"""Return an iterator over the values of a dictionary."""
return iter(getattr(d, _itervalues)())
def iteritems(d):
"""Return an iterator over the (key, value) pairs of a dictionary."""
return iter(getattr(d, _iteritems)())
if PY3:
def b(s):
return s.encode("latin-1")
def u(s):
return s
if sys.version_info[1] <= 1:
def int2byte(i):
return bytes((i,))
else:
# This is about 2x faster than the implementation above on 3.2+
int2byte = operator.methodcaller("to_bytes", 1, "big")
import io
StringIO = io.StringIO
BytesIO = io.BytesIO
else:
def b(s):
return s
def u(s):
return unicode(s, "unicode_escape")
int2byte = chr
import StringIO
StringIO = BytesIO = StringIO.StringIO
_add_doc(b, """Byte literal""")
_add_doc(u, """Text literal""")
if PY3:
import builtins
exec_ = getattr(builtins, "exec")
def reraise(tp, value, tb=None):
if value.__traceback__ is not tb:
raise value.with_traceback(tb)
raise value
print_ = getattr(builtins, "print")
del builtins
else:
def exec_(code, globs=None, locs=None):
"""Execute code in a namespace."""
if globs is None:
frame = sys._getframe(1)
globs = frame.f_globals
if locs is None:
locs = frame.f_locals
del frame
elif locs is None:
locs = globs
exec("""exec code in globs, locs""")
exec_("""def reraise(tp, value, tb=None):
raise tp, value, tb
""")
def print_(*args, **kwargs):
"""The new-style print function."""
fp = kwargs.pop("file", sys.stdout)
if fp is None:
return
def write(data):
if not isinstance(data, basestring):
data = str(data)
fp.write(data)
want_unicode = False
sep = kwargs.pop("sep", None)
if sep is not None:
if isinstance(sep, unicode):
want_unicode = True
elif not isinstance(sep, str):
raise TypeError("sep must be None or a string")
end = kwargs.pop("end", None)
if end is not None:
if isinstance(end, unicode):
want_unicode = True
elif not isinstance(end, str):
raise TypeError("end must be None or a string")
if kwargs:
raise TypeError("invalid keyword arguments to print()")
if not want_unicode:
for arg in args:
if isinstance(arg, unicode):
want_unicode = True
break
if want_unicode:
newline = unicode("\n")
space = unicode(" ")
else:
newline = "\n"
space = " "
if sep is None:
sep = space
if end is None:
end = newline
for i, arg in enumerate(args):
if i:
write(sep)
write(arg)
write(end)
_add_doc(reraise, """Reraise an exception.""")
def with_metaclass(meta, base=object):
"""Create a base class with a metaclass."""
return meta("NewBase", (base,), {})