Removing pattern matched line from multiline string in python

Question

I have a multiline text string, that looks like:

AAAA BBBBBB
BBBB VVVV XXXX

CCCCCCCC XXXX

I'd like to come up with a small function that removes an entire line if it contains a word/phrase , so that for above if I lets say sent in 'VVV' as a paremeter the output would be:

AAAA BBBBBB

CCCCCCCC XXXX

There are many examples on stackoverflow, eg Remove lines that contain certain string, which show how to do this for a file, but I'm not sure how without opening a file.

OK, so where is your code ? and whats the problem with it ? – Mazdak Dec 15 '14 at 13:00 — Mazdak, Dec 15 '14 at 13:00

Hackaholic · Accepted Answer · 2014-12-15T13:13:30.900

9

you can use re.sub:

>>> import re
>>> my_string
'AAAA BBBBBB\nBBBB VVVV XXXX\n\nCCCCCCCC XXXX'
>>> re.sub(".*VVV.*\n?","",my_string)
'AAAA BBBBBB\n\nCCCCCCCC XXXX'

you can define a function and can do for any substring:

>>> def remove(rem,my_string):
...     return re.sub(".*"+rem+".*\n?","",my_string)
... 
>>> remove("VVV",my_string)
'AAAA BBBBBB\n\nCCCCCCCC XXXX'
>>> remove("XXX",my_string)
'AAAA BBBBBB\n\n'
>>> remove("BBB",my_string)
'\nCCCCCCCC XXXX'
>>> remove("CCCC",my_string)
'AAAA BBBBBB\nBBBB VVVV XXXX\n\n'

edited Dec 15 '14 at 13:13

answered Dec 15 '14 at 13:07

Hackaholic

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I'll accept it , although I prefer using string functions over regex if possible. – user1592380 Dec 16 '14 at 14:50

score 2 · Answer 2 · answered Dec 15 '14 at 13:02

2

>>> text = '''AAAA BBBBBB
BBBB VVVV XXXX

CCCCCCCC XXXX'''
>>> text = '\n'.join(line for line in text.split('\n') if 'VVV' not in line)
>>> print text
AAAA BBBBBB

CCCCCCCC XXXX

answered Dec 15 '14 at 13:02

jamylak

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score 1 · Answer 3 · answered Dec 15 '14 at 13:02

1

inp = "AAAA BBBBBB\nBBBB VVVV XXXX\n\nCCCCCCCC XXXX"

ans = ""
pattern = "VVVV"
for line in inp.split("\n"):

    if line.find(pattern)<0:
        ans=ans + line+"\n"
print ans

answered Dec 15 '14 at 13:02

ZdaR

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2

Python doesn't have `!`, you can use `not` instead – jamylak Dec 15 '14 at 13:04

Removing pattern matched line from multiline string in python

3 Answers3