firestar5683
47 lines
1.2 KiB
Python
47 lines
1.2 KiB
Python
from typing import Any, Callable, Dict, TypeVar
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from reactivex import Observable
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from reactivex import operators as ops
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_TKey = TypeVar("_TKey")
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_TValue = TypeVar("_TValue")
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def pluck_(
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key: _TKey,
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) -> Callable[[Observable[Dict[_TKey, _TValue]]], Observable[_TValue]]:
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"""Retrieves the value of a specified key using dict-like access (as in
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element[key]) from all elements in the Observable sequence.
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Args:
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key: The key to pluck.
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Returns a new Observable {Observable} sequence of key values.
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To pluck an attribute of each element, use pluck_attr.
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"""
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def mapper(x: Dict[_TKey, _TValue]) -> _TValue:
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return x[key]
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return ops.map(mapper)
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def pluck_attr_(prop: str) -> Callable[[Observable[Any]], Observable[Any]]:
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"""Retrieves the value of a specified property (using getattr) from
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all elements in the Observable sequence.
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Args:
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property: The property to pluck.
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Returns a new Observable {Observable} sequence of property values.
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To pluck values using dict-like access (as in element[key]) on each
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element, use pluck.
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"""
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return ops.map(lambda x: getattr(x, prop))
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__all__ = ["pluck_", "pluck_attr_"]
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