26 lines
609 B
Python
26 lines
609 B
Python
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from collections import UserDict
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from typing import Any
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class _NotPresent:
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"""
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Type for representing non-existent dictionary keys.
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See :class:`_FillableDict`
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"""
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class _FillableDict(UserDict):
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"""Use :method:`fill` to add key if not present."""
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def __init__(self, data: dict):
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self.data = data
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def fill(self, key: str, value: Any) -> None:
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if self.data.get(key, _NotPresent) is _NotPresent:
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self.data[key] = value
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d = _FillableDict({'a': None, 'b': 'BBBB'})
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d.fill('c', 'CCCCCCCCC')
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d.fill('a', 'CCCCCCCCC')
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d['a'].fill('gg', 'AAAAAAAA')
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print(d)
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