Created
November 7, 2015 08:19
-
-
Save germn/e505837846fb6b866ffb to your computer and use it in GitHub Desktop.
Universal function to return unique items in iterable
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
def unique_everseen(items: Iterable, get_hashable: Callable[[Any], Any]=None) -> Iterable: | |
""" | |
Returns generator of unique items. | |
If get_hashable(item) is not None or all elements hashable, fast method would be used. | |
""" | |
if callable(get_hashable): | |
seen = set() | |
return (i for i in items for h in (get_hashable(i),) if not (h in seen or seen.add(h))) | |
elif all(isinstance(i, collections.Hashable) for i in items): | |
seen = set() | |
return (i for i in items if not (i in seen or seen.add(i))) | |
else: | |
seen = list() | |
return (i for i in items if not (i in seen or seen.append(i))) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment