CODEWITHSUNDEEP
python
vlad
vlad

Reputation: 811

Return True if item is empty string

Please consider this snippet:

>>> i = ["", 1, 2]
>>> all([x for x in i])
False

What would be Pythonic way to make this snippet return True even if item in iterable is empty string?

Standard restrictions should apply - if item is None or False etc, it should return False as expected.

Upvotes: 0

Views: 229

Answers (4)

BPL
BPL

Reputation: 9863

You can use all, for instance:

tests = [
    [None, False, "", 1, 2],
    ["", 1, 2],
    [1, 2],
    []
]

for i in tests:
    print i
    print all(filter(lambda x: x != '', i))
    print all(True if x == '' else x for x in i)
    print '-' * 80

Upvotes: -1

Darth Kotik
Darth Kotik

Reputation: 2361

This option looks nice to me.

all(x or x=="" for x in i)

Upvotes: 2

Two-Bit Alchemist
Two-Bit Alchemist

Reputation: 18467

all([x for x in i if not isinstance(x, str)])

The only falsy string is the empty string, so if you don't want to test for it, then filter out the strings.

Upvotes: 1

Kasravnd
Kasravnd

Reputation: 107347

>>> lst = ["", 1, 2]
>>> 
>>> all(True if i=='' else i for i in lst)
True

If you want True if there is at least one item that evaluates to True use any().

>>> any(lst)
True

Note that in general any() and all() accept iterable argument and you don't need to loop over them.

Upvotes: 2

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