36 lines
1.0 KiB
Python
36 lines
1.0 KiB
Python
from typing import Any, Callable, TYPE_CHECKING
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if TYPE_CHECKING:
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standard_cached_property = None
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else:
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try:
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from functools import cached_property as standard_cached_property
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except ImportError: # Python < 3.8
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standard_cached_property = None
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if standard_cached_property:
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cached_property = standard_cached_property
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else:
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# Code taken from https://github.com/bottlepy/bottle
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class CachedProperty:
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"""A cached property.
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A property that is only computed once per instance and then replaces itself with
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an ordinary attribute. Deleting the attribute resets the property.
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"""
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def __init__(self, func: Callable) -> None:
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self.__doc__ = getattr(func, "__doc__")
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self.func = func
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def __get__(self, obj: object, cls: type) -> Any:
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if obj is None:
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return self
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value = obj.__dict__[self.func.__name__] = self.func(obj)
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return value
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cached_property = CachedProperty
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__all__ = ["cached_property"]
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