CODEWITHSUNDEEP
pythonlistexpression
Jakub Kasal
Jakub Kasal

Reputation: 13

Find a specific pattern (regular expression) in each item of list of strings (Python)

From this list problems= ["32 + 698", "3801 - 2", "45 + 43", "123 + 49"]

I want to get these numbers "\d*\s" that means 32,3801,45,123

Is there a way to look in each item of list and search there with a list comprehension ?

I have only this attempt print([x for x in problems if re.search(r'\d*\s',x)]), but it prints whole item if the "\d*\s" is there, so I get again ["32 + 698", "3801 - 2", "45 + 43", "123 + 49"]

(My aim is have a lenght of the longer number of each item, that would be 3,4,2,3)

Upvotes: 0

Views: 43

Answers (1)

let me down slowly
let me down slowly

Reputation: 987

You need to extract the first part before space in your strings. This can be done using group capturing. Here is the code you can use:

[re.search('(\d+)\s', x).group(1) for x in problems if re.search(r'(\d)*\s',x)]

Here (\d+)\s matches for one or more digits before a whitespace character and we extract the first group using the group(1) method.

Upvotes: 1

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