replace a string containing a substring with a string in Python

Question

I need to replace a string containing a substring with another string. For example:

biography -> biography
biographical -> biography
biopic -> biography
bio-pic -> biography-pic
I watched a biographical movie -> I watched a biography movie

Here, all words on the left contain bio, so the whole word is replaced by biography. I am aware of string.replace() function, but it doesn't seem to work well here. I looked up regular expressions, but I'm not sure if re is the right library to solve the problem.

@SukumarRdjf Good question, I suspect that the problem is that it maps biography to biographygraphy — John Coleman
– John Coleman, Commented Dec 13, 2019 at 18:24
First split string to words then apply suggestion of @SubhrajyotiDas to each word. — Michael Butscher
– Michael Butscher, Commented Dec 13, 2019 at 18:25
@Sukumar-Rdjf I mean that I don't want to construct the dictionary consisting of all possible words containing bio, and then call string.replace(word, bio) for every such word — diplo
– diplo, Commented Dec 13, 2019 at 18:27
Are you certain that you won't have things like 'biology' which have nothing to do with 'biography' but nevertheless contain 'bio'? — John Coleman
– John Coleman, Commented Dec 13, 2019 at 18:30

DarrylG · Accepted Answer · 2019-12-13 18:34:33Z

1

Using Regex

import re

s = """
biography -> biography
biographical -> biography
biopic -> biography
bio-pic -> biography-pic
I watched a biographical movie -> I watched a biography movie
"""
x = re.sub(r'\b(bio\w*)', 'biography', s)
print(x)

Output

biography -> biography
biography -> biography
biography -> biography
biography-pic -> biography-pic
I watched a biography movie -> I watched a biography movie

answered Dec 13, 2019 at 18:34

DarrylG

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Comments

WGriffing · Accepted Answer · 2019-12-13 18:36:32Z

import re

search_string = 'bio'
replace_string = 'biography'
vals = ['biography', 'biographical', 'biopic', 'bio-pic', 'something else', 'bio pic', 'I watched a biographical movie']
altered = [re.sub(re.escape(search_string)+r'\w*',replace_string,val) for val in vals]
print(altered)

outputs

['biography', 'biography', 'biography', 'biography-pic', 'something else', 'biography pic', 'I watched a biography movie']

For the regex part, re.escape() can be used to turn a variable into a regular expression. I assumed your 'bio' search string will not be constant. The rest of it \w* means to match 0 or more (the *) of the preceding character. \w means word characters (a-z, A-Z, 0-9, and _). Since we're only matching word characters, it stops the match when a space is encountered.

M Hamza Razzaq · Accepted Answer · 2019-12-13 18:37:05Z

0

Try regular expression to solve this problem. It will definitely. You can change regular expression according to your requirement. Here is an example code

import re
s = "biography biographical biopic bio-pic I watched a biographical movie"
replaced = re.sub('(bio[A-Za-z]*)', 'biography', s)
print (replaced )

answered Dec 13, 2019 at 18:37

M Hamza Razzaq

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Comments

karavanjo · Accepted Answer · 2019-12-13 18:38:00Z

0

One of the decisions:

import re

def f(s, pat, replace):
    pat = r'(\w*%s\w*)' % pat
    return re.sub(pat, "biography", s)

input = """
biography -> biography
biographical -> biography
biopic -> biography
bio-pic -> biography-pic
I watched a biographical movie -> I watched a biography movie
"""

c = f(input, "bio", "biography")
print(c)

Output:

biography -> biography
biography -> biography
biography -> biography
biography-pic -> biography-pic
I watched a biography movie -> I watched a biography movie

answered Dec 13, 2019 at 18:38

karavanjo

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