Insert string in pandas column using regex if pattern is found

Question

I have a string column in a dataframe and I'd like to insert a # to the begging of my pattern.

For example: My pattern is the letters 'pr' followed by any amount of numbers. If in my column there is a value 'problem in pr123', I would change it to 'problem in #pr123'.

I'm trying a bunch of code snippets but nothing is working for me.

Tried to change the solution to replace for 'pr#123' but this didn't work either.

df['desc_clean'] = df['desc_clean'].str.replace(r'([p][r])(\d+)', r'\1#\2', regex=True)

What's the best way I can replace all values in this column when I find this pattern?

You need df['desc_clean'] = df['desc_clean'].str.replace(r'(pr)(\d+)', r'\1#\2') if you need pr#123. To get #pr123, you need df['desc_clean'].str.replace(r'pr\d+', r'#\g<0>'). Add a word boundary, \b, in front of pr to match pr as a whole word. — Wiktor Stribiżew
– Wiktor Stribiżew, Commented Aug 25, 2020 at 19:46
This worked great! Thank you so much for your help @WiktorStribiżew — eduardoftdo
– eduardoftdo, Commented Aug 25, 2020 at 19:54

Wiktor Stribiżew · Accepted Answer · 2020-08-25 20:01:29Z

2

If you need pr#123 you can use

df['desc_clean'] = df['desc_clean'].str.replace(r'(pr)(\d+)', r'\1#\2')

To get #pr123, you can use

df['desc_clean'].str.replace(r'pr\d+', r'#\g<0>')

To match pr as a whole word, you can add a word boundary, \b, in front of pr:

df['desc_clean'].str.replace(r'\bpr\d+', r'#\g<0>')

See the regex demo.

answered Aug 25, 2020 at 20:01

Wiktor Stribiżew

631k41 gold badges502 silver badges632 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

eduardoftdo Over a year ago

This works great and solved my problem. Thanks for the help Wiktor!

Collectives™ on Stack Overflow

Insert string in pandas column using regex if pattern is found

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related