python - How to strip a specific word from a string?

65
votes

I need to strip a specific word from a string.

But I find python strip method seems can't recognize an ordered word. The just strip off any characters passed to the parameter.

For example:

>>> papa = "papa is a good man"
>>> app = "app is important"
>>> papa.lstrip('papa')
" is a good man"
>>> app.lstrip('papa')
" is important"

How could I strip a specified word with python?

7
pythonstringstrip
Did you look at the documentation of S.lstrip? It does something completely different to what you want to do. You want to replace this string with nothing. - Benjamin Bannier
What do you want to happen to the word "papaya"? - DSM
@DSM I guess the output should be ya. Lets wait for OP to confirm - thefourtheye
@zen Are you sure the accepted answer is fine? Try this print "papa is papa is papa".replace('papa', '') and if the output is fine with you, then the accepted answer is correct. - thefourtheye
Just wanted to add something. Beware that if you are attempting to strip the last word in a sentence then you will be left with a space at the end of the sentence and this may not be desired. For example if you did papa.replace('man', ''). You will end up with 'papa is a good ' (notice the space after 'good'. - Ely Fialkoff

7 Answers

93
votes

Use str.replace.

>>> papa.replace('papa', '')
' is a good man'
>>> app.replace('papa', '')
'app is important'

Alternatively use re and use regular expressions. This will allow the removal of leading/trailing spaces.

>>> import re
>>> papa = 'papa is a good man'
>>> app = 'app is important'
>>> papa3 = 'papa is a papa, and papa'
>>>
>>> patt = re.compile('(\s*)papa(\s*)')
>>> patt.sub('\\1mama\\2', papa)
'mama is a good man'
>>> patt.sub('\\1mama\\2', papa3)
'mama is a mama, and mama'
>>> patt.sub('', papa3)
'is a, and'
15
votes

Easiest way would be to simply replace it with an empty string.

s = s.replace('papa', '')
4
votes

You can also use a regexp with re.sub:

article_title_str = re.sub(r'(\s?-?\|?\s?Times of India|\s?-?\|?\s?the Times of India|\s?-?\|?\s+?Gadgets No'',
                           article_title_str, flags=re.IGNORECASE)
3
votes

Providing you know the index value of the beginning and end of each word you wish to replace in the character array, and you only wish to replace that particular chunk of data, you could do it like this. 

>>> s = "papa is papa is papa"
>>> s = s[:8]+s[8:13].replace("papa", "mama")+s[13:]
>>> print(s)
papa is mama is papa

Alternatively, if you also wish to retain the original data structure, you could store it in a dictionary.

>>> bin = {}
>>> s = "papa is papa is papa"
>>> bin["0"] = s
>>> s = s[:8]+s[8:13].replace("papa", "mama")+s[13:]
>>> print(bin["0"])
papa is papa is papa
>>> print(s)
papa is mama is papa
2
votes

A bit 'lazy' way to do this is to use startswith- it is easier to understand this rather regexps. However regexps might work faster, I haven't measured.

>>> papa = "papa is a good man"
>>> app = "app is important"
>>> strip_word = 'papa'
>>> papa[len(strip_word):] if papa.startswith(strip_word) else papa
' is a good man'
>>> app[len(strip_word):] if app.startswith(strip_word) else app
'app is important'
0
votes

If want to remove the word from only the start of the string, then you could do:

  string[string.startswith(prefix) and len(prefix):]

Where string is your string variable and prefix is the prefix you want to remove from your string variable.

For example:

  >>> papa = "papa is a good man. papa is the best."  
  >>> prefix = 'papa'
  >>> papa[papa.startswith(prefix) and len(prefix):]
  ' is a good man. papa is the best.'
0
votes

Check it:

use replace()
------------
var.replace("word for replace"," ")
-----------------------------------
one = " papa is a good man"

two = " app is important"

one.replace(" papa ", " ")

output=> " is a good man"

two.replace(" app ", " ")

output=> " is important