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Regex expression for words with length of even number

Neo

I want to write a regex expression for words with even-numbered length.

For example, the output I want from the list containing the words:
{"blue", "ah", "sky", "wow", "neat"} is {"blue", "ah", "neat}.

I know that the expression w{2} or w{4} would produce 2-worded or 4-worded words, but what I want is something that could work for all even numbers. I tried using w{%2==0} but it doesn’t work.

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Answer

You can repeat 2 word characters as a group between anchors ^ to assert the start and $ to assert the end of the string, or between word boundaries b

^(?:w{2})+$

See a regex demo.

import re

strings = [
    "blue",
    "ah",
    "sky",
    "wow",
    "neat"
]

for s in strings:
    m = re.match(r"(?:w{2})+$", s)
    if m:
        print(m.group())

Output

blue
ah
neat
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