38 lines
1.1 KiB
Python
38 lines
1.1 KiB
Python
# This file is dual licensed under the terms of the Apache License, Version
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# 2.0, and the BSD License. See the LICENSE file in the root of this repository
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# for complete details.
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from __future__ import absolute_import, division, print_function
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import sys
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from ._typing import TYPE_CHECKING
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if TYPE_CHECKING: # pragma: no cover
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from typing import Any, Dict, Tuple, Type
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PY2 = sys.version_info[0] == 2
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PY3 = sys.version_info[0] == 3
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# flake8: noqa
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if PY3:
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string_types = (str,)
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else:
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string_types = (basestring,)
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def with_metaclass(meta, *bases):
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# type: (Type[Any], Tuple[Type[Any], ...]) -> Any
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"""
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Create a base class with a metaclass.
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"""
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# This requires a bit of explanation: the basic idea is to make a dummy
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# metaclass for one level of class instantiation that replaces itself with
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# the actual metaclass.
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class metaclass(meta): # type: ignore
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def __new__(cls, name, this_bases, d):
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# type: (Type[Any], str, Tuple[Any], Dict[Any, Any]) -> Any
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return meta(name, bases, d)
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return type.__new__(metaclass, "temporary_class", (), {})
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