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| author | Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> | 2024-06-01 17:06:04 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2024-06-01 17:06:04 (GMT) |
| commit | 99d0f51e61b6ab3d58c034c007b5d9d6156fdf3b (patch) | |
| tree | 7301f4319ed6443735a3b608ffe8fef16f087823 | |
| parent | 9f9be95d66c0dd66189f8c9f13b69442361cd593 (diff) | |
| download | cpython-99d0f51e61b6ab3d58c034c007b5d9d6156fdf3b.zip cpython-99d0f51e61b6ab3d58c034c007b5d9d6156fdf3b.tar.gz cpython-99d0f51e61b6ab3d58c034c007b5d9d6156fdf3b.tar.bz2 | |
[3.13] Add unique() recipe to itertools docs (gh-119911) (gh-119916)
| -rw-r--r-- | Doc/library/itertools.rst | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst index 121bfd3..3dc3f60 100644 --- a/Doc/library/itertools.rst +++ b/Doc/library/itertools.rst @@ -857,7 +857,7 @@ and :term:`generators <generator>` which incur interpreter overhead. return len(take(2, groupby(iterable, key))) <= 1 def unique_justseen(iterable, key=None): - "List unique elements, preserving order. Remember only the element just seen." + "Yield unique elements, preserving order. Remember only the element just seen." # unique_justseen('AAAABBBCCDAABBB') → A B C D A B # unique_justseen('ABBcCAD', str.casefold) → A B c A D if key is None: @@ -865,7 +865,7 @@ and :term:`generators <generator>` which incur interpreter overhead. return map(next, map(operator.itemgetter(1), groupby(iterable, key))) def unique_everseen(iterable, key=None): - "List unique elements, preserving order. Remember all elements ever seen." + "Yield unique elements, preserving order. Remember all elements ever seen." # unique_everseen('AAAABBBCCDAABBB') → A B C D # unique_everseen('ABBcCAD', str.casefold) → A B c D seen = set() @@ -880,6 +880,11 @@ and :term:`generators <generator>` which incur interpreter overhead. seen.add(k) yield element + def unique(iterable, key=None, reverse=False): + "Yield unique elements in sorted order. Supports unhashable inputs." + # unique([[1, 2], [3, 4], [1, 2]]) → [1, 2] [3, 4] + return unique_justseen(sorted(iterable, key=key, reverse=reverse), key=key) + def sliding_window(iterable, n): "Collect data into overlapping fixed-length chunks or blocks." # sliding_window('ABCDEFG', 4) → ABCD BCDE CDEF DEFG @@ -1605,6 +1610,13 @@ The following recipes have a more mathematical flavor: >>> ''.join(input_iterator) 'AAABBBCCDAABBB' + >>> list(unique([[1, 2], [3, 4], [1, 2]])) + [[1, 2], [3, 4]] + >>> list(unique('ABBcCAD', str.casefold)) + ['A', 'B', 'c', 'D'] + >>> list(unique('ABBcCAD', str.casefold, reverse=True)) + ['D', 'c', 'B', 'A'] + >>> d = dict(a=1, b=2, c=3) >>> it = iter_except(d.popitem, KeyError) >>> d['d'] = 4 |