14 lines
363 B
Python
14 lines
363 B
Python
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from functools import reduce # <1>
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from operator import add
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from typing import overload, Iterable, Union, TypeVar
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T = TypeVar('T')
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S = TypeVar('S') # <2>
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@overload
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def sum(it: Iterable[T]) -> Union[T, int]: ... # <3>
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@overload
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def sum(it: Iterable[T], /, start: S) -> Union[T, S]: ... # <4>
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def sum(it, /, start=0): # <5>
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return reduce(add, it, start)
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