"""
Python 2.6, 2.7, and 3.x compatibility.

"""
import sys


is_py2 = sys.version_info[0] == 2
is_py26 = sys.version_info[:2] == (2, 6)
is_py27 = sys.version_info[:2] == (2, 7)
is_py3 = sys.version_info[0] == 3
is_pypy = 'pypy' in sys.version.lower()
is_windows = 'win32' in str(sys.platform).lower()


if is_py2:
    # noinspection PyShadowingBuiltins
    bytes = str
    # noinspection PyUnresolvedReferences,PyShadowingBuiltins
    str = unicode
elif is_py3:
    # noinspection PyShadowingBuiltins
    str = str
    # noinspection PyShadowingBuiltins
    bytes = bytes


try:  # pragma: no cover
    # noinspection PyUnresolvedReferences,PyCompatibility
    from urllib.parse import urlsplit
except ImportError:  # pragma: no cover
    # noinspection PyUnresolvedReferences,PyCompatibility
    from urlparse import urlsplit

try:  # pragma: no cover
    # noinspection PyCompatibility
    from urllib.request import urlopen
except ImportError:  # pragma: no cover
    # noinspection PyCompatibility,PyUnresolvedReferences
    from urllib2 import urlopen

try:  # pragma: no cover
    from collections import OrderedDict
except ImportError:  # pragma: no cover
    # Python 2.6 OrderedDict class, needed for headers, parameters, etc .###
    # <https://pypi.python.org/pypi/ordereddict/1.1>
    # noinspection PyCompatibility,PyUnresolvedReferences
    from UserDict import DictMixin

    # noinspection PyShadowingBuiltins,PyCompatibility
    class OrderedDict(dict, DictMixin):
        # Copyright (c) 2009 Raymond Hettinger
        #
        # 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.
        # noinspection PyMissingConstructor
        def __init__(self, *args, **kwds):
            if len(args) > 1:
                raise TypeError('expected at most 1 arguments, got %d'
                                % len(args))
            try:
                self.__end
            except AttributeError:
                self.clear()
            self.update(*args, **kwds)

        def clear(self):
            self.__end = end = []
            # noinspection PyUnusedLocal
            end += [None, end, end]     # sentinel node for doubly linked list
            self.__map = {}             # key --> [key, prev, next]
            dict.clear(self)

        def __setitem__(self, key, value):
            if key not in self:
                end = self.__end
                curr = end[1]
                curr[2] = end[1] = self.__map[key] = [key, curr, end]
            dict.__setitem__(self, key, value)

        def __delitem__(self, key):
            dict.__delitem__(self, key)
            key, prev, next = self.__map.pop(key)
            prev[2] = next
            next[1] = prev

        def __iter__(self):
            end = self.__end
            curr = end[2]
            while curr is not end:
                yield curr[0]
                curr = curr[2]

        def __reversed__(self):
            end = self.__end
            curr = end[1]
            while curr is not end:
                yield curr[0]
                curr = curr[1]

        def popitem(self, last=True):
            if not self:
                raise KeyError('dictionary is empty')
            if last:
                # noinspection PyUnresolvedReferences
                key = reversed(self).next()
            else:
                key = iter(self).next()
            value = self.pop(key)
            return key, value

        def __reduce__(self):
            items = [[k, self[k]] for k in self]
            tmp = self.__map, self.__end
            del self.__map, self.__end
            inst_dict = vars(self).copy()
            self.__map, self.__end = tmp
            if inst_dict:
                return self.__class__, (items,), inst_dict
            return self.__class__, (items,)

        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

        def __repr__(self):
            if not self:
                return '%s()' % (self.__class__.__name__,)
            return '%s(%r)' % (self.__class__.__name__, self.items())

        def copy(self):
            return self.__class__(self)

        # noinspection PyMethodOverriding
        @classmethod
        def fromkeys(cls, iterable, value=None):
            d = cls()
            for key in iterable:
                d[key] = value
            return d

        def __eq__(self, other):
            if isinstance(other, OrderedDict):
                if len(self) != len(other):
                    return False
                for p, q in zip(self.items(), other.items()):
                    if p != q:
                        return False
                return True
            return dict.__eq__(self, other)

        def __ne__(self, other):
            return not self == other