Regex expression with [ and * in python

Question

I have a file with lines like this

variable = epms[something][something]

I need to find these lines by searching for epms.

Currently, I am trying this:

regex = re.compile('[.]*epms\[[.]*\]\[[.]*\][.]*')

However this doesn't find any match. What am I doing wrong?

`[.]` matches a literal dot char. You need to remove the `[]` around `.`s. — Wiktor Stribiżew, Aug 13 '18 at 07:56
Also, see https://stackoverflow.com/questions/19976018/does-a-dot-have-to-be-escaped-in-a-character-class-square-brackets-of-a-regula — Wiktor Stribiżew, Aug 13 '18 at 08:01

score 2 · Accepted Answer · answered Aug 13 '18 at 08:13

2

You can use pattern:

epms\[[^]]+\]\[[^]]+\]

epms Match literal substring.
\[ Match a [.
[^]]+ Negated character set. Anything other than a ].
\] Match a ].
\[ Match a [.
[^]]+ Negated character set. Anything other than a ].
\] Match a ].

In Python:

import re

mystring = "variable = epms[something][something]"
if re.search(r'epms\[[^]]+\]\[[^]]+\]',mystring):
    print (mystring)

answered Aug 13 '18 at 08:13

Paolo

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Thanks for the full explanation! – fangio Aug 13 '18 at 13:50

score 1 · Answer 2 · answered Aug 13 '18 at 07:57

1

Try this pattern epms\[.*\]\[.*\].

Ex:

import re

with open(filename1) as infile:
    for line in infile:
        if re.search(r"epms\[.*\]\[.*\]", line):
            print(line)

answered Aug 13 '18 at 07:57

Rakesh

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score 0 · Answer 3 · answered Aug 13 '18 at 08:17

Try this, tested in Python3:

>>> s = 'variable = epms[something][something]'
>>> re.match(r'.*epms\[.*\]\[.*\]', s)
<_sre.SRE_Match object; span=(0, 37), match='variable = epms[something][something]'>

You don't need square brackets to identify 'any characters'.

Regex expression with [ and * in python

3 Answers3