re.sub with variables, whole string by itself only

Question

Column 1 in my csv has the target_string (to be replaced) and column 2 is the context (text_column). I can't get it to only remove the string when it is stand alone. I have tried adding \b, but that doesn't work.

Text : "Foo, FOOBAR FOO FOOBAR FOO FOO FOOBAR."

string_column = col [1]
text_column = col [2]
string_replacement = "BAR"

text_column = re.sub(string_column, string_replacement, text_column, flags=re.IGNORECASE)

What I get is : "BARBAR BAR BARBAR BAR BAR BARBAR."

What I need is: "FOOBAR BAR FOOBAR BAR BAR FOOBAR."

EDIT I don't think this is a duplicate of the linked question. Those responses wouldn't have helped me, and are far more complicated than the simple solution provided here.

You haven't shown how your `\b` was added and it doesn't work. — Moses Koledoye, Dec 04 '17 at 17:11
@MosesKoledoye sorry I didn't want to post the broken code, I just posted the one that I got to work, just not 100%.. I had added \b before and after `string_column` in the `re.sub` and it gave an error — chrissmit.yam90, Dec 04 '17 at 17:15
@Gurman I can't do that because it is not always `Foo`. I am using the variable `string_column` because the target string will change for each run. — chrissmit.yam90, Dec 04 '17 at 17:16
so what you tried, which did not work, was `text_column = re.sub(\bstring_column\b, string_replacement, text_column, flags=re.IGNORECASE)`..? — physlexic, Dec 04 '17 at 17:21
I don't see the "duplication".. same topic, different environment/requirements — physlexic, Dec 07 '17 at 16:11

Jan · Accepted Answer · 2017-12-04T17:21:48.197

3

You (probably) need \b on both sides:

import re

string = "Foo, FOOBAR FOO FOOBAR FOO FOO FOOBAR."

your_string_here = "FOO"
string_column = r"\b{}\b".format(your_string_here)
string_replacement = "BAR"

string = re.sub(string_column, 'BAR', string)
print(string)

This yields

Foo, FOOBAR BAR FOOBAR BAR BAR FOOBAR.

edited Dec 04 '17 at 17:21

answered Dec 04 '17 at 17:11

Jan

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thank you, but I need to keep the variables.. this works, but the target string will not always be 'FOO'.. which is why I defined the variable as `col [1]` – chrissmit.yam90 Dec 04 '17 at 17:20
1

@chrissmit.yam90: See the updated answer then. – Jan Dec 04 '17 at 17:22
thank you, this works.. i didn't think to add another processing step, i was tunneled into just editing the `re.sub` – chrissmit.yam90 Dec 04 '17 at 17:46

re.sub with variables, whole string by itself only

1 Answers1