Regex in python: combining 2 regex expressions into one

Question

Suppose I have the following list:

a = ['35','years','opened','7,000','churches','rev.','mr.','brandt','said','adding','denomination','national','goal','one','church','every','10,000','persons']

I want to remove all elements, that contain numbers and elements, that end with dots. So I want to delete '35','7,000','10,000','mr.','rev.'

I can do it separately using the following regex:

regex = re.compile('[a-zA-Z\.]')
regex2 = re.compile('[0-9]')

But when I try to combine them I delete either all elements or nothing. How can I combine two regex correctly?

"I can do it separately using the following regex:" -- I am sorry but I don't believe you. The regex [a-zA-Z\.] matches any single character in that set, and so it will NOT only remove "elements, that end with dots". It will also remove every upper and lowercase letter in your entire string. — Jongware
– Jongware, Commented Feb 12, 2020 at 14:14

tsumarios · Accepted Answer · 2020-02-12 17:23:41Z

2

This should work:

reg = re.compile('[a-zA-Z]+\.|[0-9,]+')

Note that your first regex is wrong because it deletes any string within a dot inside it. To avoid this, I included [a-zA-Z]+\. in the combined regex. Your second regex is also wrong as it misses a "+" and a ",", which I included in the above solution. Here a demo.

Also, if you assume that elements which end with a dot might contain some numbers the complete solution should be:

reg = re.compile('[a-zA-Z0-9]+\.|[0-9,]+')

edited Feb 12, 2020 at 17:23

answered Feb 12, 2020 at 14:13

tsumarios

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1 Comment

Toto Over a year ago

@liverToll92: This doesn't work

BadHorsie · Accepted Answer · 2020-02-12 15:04:04Z

1

If you don't need to capture the result, this matches any string with a dot at the end, or any with a number in it.

\.$|\d

answered Feb 12, 2020 at 15:04

BadHorsie

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Comments

Jan · Accepted Answer · 2020-02-12 17:13:18Z

1

You could use:

(?:[^\d\n]*\d)|.*\.$

See a demo on regex101.com.

edited Feb 12, 2020 at 17:13

answered Feb 12, 2020 at 14:07

Jan

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Toto Over a year ago

This doesn't match 35 or 7,000

Toto · Accepted Answer · 2020-02-12 15:10:21Z

0

Here is a way to do the job:

import re

a = ['35','years','opened','7,000','churches','rev.','mr.','brandt','said','adding','denomination','national','goal','one','church','every','10,000','per.sons']
b = []
for s in a:
    if not re.search(r'^(?:[\d,]+|.*\.)$', s):
        b.append(s)
print b

Output:

['years', 'opened', 'churches', 'brandt', 'said', 'adding', 'denomination', 'national', 'goal', 'one', 'church', 'every', 'per.sons']

Demo & explanation

answered Feb 12, 2020 at 15:10

Toto

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