| """Common collection classes.""" |
| from functools import reduce |
| from collections.abc import Mapping, Set |
|
|
| from frozendict import frozendict |
|
|
| from ..deprecations import deprecated |
| from ..common.compat import isiterable |
|
|
|
|
| |
| class AttrDict(dict): |
| """Sub-classes dict, and further allows attribute-like access to dictionary items. |
| |
| Examples: |
| >>> d = AttrDict({'a': 1}) |
| >>> d.a, d['a'], d.get('a') |
| (1, 1, 1) |
| >>> d.b = 2 |
| >>> d.b, d['b'] |
| (2, 2) |
| """ |
| def __init__(self, *args, **kwargs): |
| super().__init__(*args, **kwargs) |
| self.__dict__ = self |
|
|
|
|
| def first(seq, key=bool, default=None, apply=lambda x: x): |
| """Give the first value that satisfies the key test. |
| |
| Args: |
| seq (iterable): |
| key (callable): test for each element of iterable |
| default: returned when all elements fail test |
| apply (callable): applied to element before return, but not to default value |
| |
| Returns: first element in seq that passes key, mutated with optional apply |
| |
| Examples: |
| >>> first([0, False, None, [], (), 42]) |
| 42 |
| >>> first([0, False, None, [], ()]) is None |
| True |
| >>> first([0, False, None, [], ()], default='ohai') |
| 'ohai' |
| >>> import re |
| >>> m = first(re.match(regex, 'abc') for regex in ['b.*', 'a(.*)']) |
| >>> m.group(1) |
| 'bc' |
| |
| The optional `key` argument specifies a one-argument predicate function |
| like that used for `filter()`. The `key` argument, if supplied, must be |
| in keyword form. For example: |
| >>> first([1, 1, 3, 4, 5], key=lambda x: x % 2 == 0) |
| 4 |
| |
| """ |
| return next((apply(x) for x in seq if key(x)), default() if callable(default) else default) |
|
|
|
|
| def last(seq, key=bool, default=None, apply=lambda x: x): |
| return next((apply(x) for x in reversed(seq) if key(x)), default) |
|
|
