How do I match something between brackets using regex?

Question

import re
string1 = 'thisIsSomeText    [128Kb]'
print(string1)
string2 = re.sub('[*]', '', string1)
print(string2)

thisIsSomeText    [128Kb]
thisIsSomeText    [128Kb]

my issue is that I need to remove [filesize] from the end of a string. The syntax is killing me here and im struggling to understand what the proper format is for this.

Does this answer your question? [What's the regular expression that matches a square bracket?](https://stackoverflow.com/questions/928072/whats-the-regular-expression-that-matches-a-square-bracket) — AMC, Sep 18 '20 at 20:23

score 2 · Accepted Answer · answered Sep 18 '20 at 19:47

2

You would need to escape your [ and ] characters with \

>>> import re
>>> string1 = 'thisIsSomeText    [128Kb]'
>>> re.sub(r'\[.*\]', '', string1)
'thisIsSomeText    '

You could also str.strip afterwards to remove the trailing whitespace

>>> re.sub(r'\[.*\]', '', string1).strip()
'thisIsSomeText'

answered Sep 18 '20 at 19:47

Cory Kramer

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okay i understand escaping the brackets now. but what is the purpose of the ```.``` in there – Maxwell Sep 18 '20 at 19:51
The `.` means "any character" and `*` means "0 or more", so together `.*` means "0 or more of any character" between your brackets – Cory Kramer Sep 18 '20 at 19:52
@Maxwell, here's a pretty handy tool that you can use to explain and test regular expressions https://regex101.com/r/6F8Uwd/1 – Pranav Hosangadi Sep 18 '20 at 19:53
@Maxwell Star `*` is a *suffix* meaning "zero or more", so `\[*` would mean "zero or more open-brackets", which is not what you want. `.` means "any character except a newline". – wjandrea Sep 18 '20 at 19:54

How do I match something between brackets using regex?

1 Answers1