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""" Compatibility layer.
Some py2/py3 compatibility support based on a stripped down
version of six so we don't have to depend on a specific version
of it.
:copyright: (c) 2014 by Armin Ronacher.
:license: BSD
"""
import sys
PY2 = sys.version_info[0] == 2
_identity = lambda x: x
if not PY2:
text_type = str
string_types = (str,)
integer_types = (int, )
iterkeys = lambda d: iter(d.keys())
itervalues = lambda d: iter(d.values())
iteritems = lambda d: iter(d.items())
from io import StringIO
def reraise(tp, value, tb=None):
if value.__traceback__ is not tb:
raise value.with_traceback(tb)
raise value
implements_to_string = _identity
def exec_in(code, glob, loc=None):
if isinstance(code, str):
code = compile(code, '<string>', 'exec', dont_inherit=True)
exec(code, glob, loc)
else:
text_type = unicode
string_types = (str, unicode)
integer_types = (int, long)
iterkeys = lambda d: d.iterkeys()
itervalues = lambda d: d.itervalues()
iteritems = lambda d: d.iteritems()
from cStringIO import StringIO
exec('def reraise(tp, value, tb=None):\n raise tp, value, tb')
def implements_to_string(cls):
cls.__unicode__ = cls.__str__
cls.__str__ = lambda x: x.__unicode__().encode('utf-8')
return cls
exec("""def exec_in(code, glob, loc=None):
if isinstance(code, basestring):
code = compile(code, '<string>', 'exec', dont_inherit=True)
exec code in glob, loc
""")
def with_metaclass(meta, *bases):
# This requires a bit of explanation: the basic idea is to make a
# dummy metaclass for one level of class instantiation that replaces
# itself with the actual metaclass. Because of internal type checks
# we also need to make sure that we downgrade the custom metaclass
# for one level to something closer to type (that's why __call__ and
# __init__ comes back from type etc.).
#
# This has the advantage over six.with_metaclass in that it does not
# introduce dummy classes into the final MRO.
class metaclass(meta):
__call__ = type.__call__
__init__ = type.__init__
def __new__(cls, name, this_bases, d):
if this_bases is None:
return type.__new__(cls, name, (), d)
return meta(name, bases, d)
return metaclass('temporary_class', None, {})
# Certain versions of pypy have a bug where clearing the exception stack
# breaks the __exit__ function in a very peculiar way. This is currently
# true for pypy 2.2.1 for instance. The second level of exception blocks
# is necessary because pypy seems to forget to check if an exception
# happend until the next bytecode instruction?
BROKEN_PYPY_CTXMGR_EXIT = False
if hasattr(sys, 'pypy_version_info'):
class _Mgr(object):
def __enter__(self):
return self
def __exit__(self, *args):
sys.exc_clear()
try:
try:
with _Mgr():
raise AssertionError()
except:
raise
except TypeError:
BROKEN_PYPY_CTXMGR_EXIT = True
except AssertionError:
pass
try:
from collections import OrderedDict
except ImportError:
from UserDict import DictMixin
class OrderedDict(dict, DictMixin):
null = object()
def __init__(self, *args, **kwargs):
self.clear()
self.update(*args, **kwargs)
def clear(self):
self.__map = dict()
self.__order = list()
dict.clear(self)
def __setitem__(self, key, value):
if key not in self:
self.__map[key] = len(self.__order)
self.__order.append(key)
dict.__setitem__(self, key, value)
def __delitem__(self, key):
dict.__delitem__(self, key)
self.__map.pop(key)
self.__order = self.null
def __iter__(self):
for key in self.__order:
if key is not self.null:
yield key
def keys(self):
return list(self)
setdefault = DictMixin.setdefault
update = DictMixin.update
pop = DictMixin.pop
values = DictMixin.values
items = DictMixin.items
iterkeys = DictMixin.iterkeys
itervalues = DictMixin.itervalues
iteritems = DictMixin.iteritems
try:
from importlib import import_module
except ImportError:
def _resolve_name(name, package, level):
"""Return the absolute name of the module to be imported."""
if not hasattr(package, 'rindex'):
raise ValueError("'package' not set to a string")
dot = len(package)
for x in xrange(level, 1, -1):
try:
dot = package.rindex('.', 0, dot)
except ValueError:
raise ValueError("attempted relative import beyond top-level package")
return "%s.%s" % (package[:dot], name)
def import_module(name, package=None):
"""Import a module.
The 'package' argument is required when performing a relative import. It
specifies the package to use as the anchor point from which to resolve the
relative import to an absolute import.
"""
if name.startswith('.'):
if not package:
raise TypeError("relative imports require the 'package' argument")
level = 0
for character in name:
if character != '.':
break
level += 1
name = _resolve_name(name[level:], package, level)
__import__(name)
return sys.modules[name]
# pylama:ignore=W,E731,C901
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