Remove all whitespace in a string – Dev

The best answers to the question “Remove all whitespace in a string” in the category Dev.

QUESTION:

I want to eliminate all the whitespace from a string, on both ends, and in between words.

I have this Python code:

def my_handle(self):
    sentence=" hello  apple  "
    sentence.strip()

But that only eliminates the whitespace on both sides of the string. How do I remove all whitespace?

ANSWER:

To remove only spaces use str.replace:

sentence = sentence.replace(' ', '')

To remove all whitespace characters (space, tab, newline, and so on) you can use split then join:

sentence="".join(sentence.split())

or a regular expression:

import re
pattern = re.compile(r'\s+')
sentence = re.sub(pattern, '', sentence)

If you want to only remove whitespace from the beginning and end you can use strip:

sentence = sentence.strip()

You can also use lstrip to remove whitespace only from the beginning of the string, and rstrip to remove whitespace from the end of the string.

ANSWER:

If you want to remove leading and ending spaces, use str.strip():

sentence=" hello  apple"
sentence.strip()
>>> 'hello  apple'

If you want to remove all space characters, use str.replace():

(NB this only removes the “normal” ASCII space character ' ' U+0020 but not any other whitespace)

sentence=" hello  apple"
sentence.replace(" ", "")
>>> 'helloapple'

If you want to remove duplicated spaces, use str.split():

sentence=" hello  apple"
" ".join(sentence.split())
>>> 'hello apple'

ANSWER:

“Whitespace” includes space, tabs, and CRLF. So an elegant and one-liner string function we can use is str.translate:

Python 3

' hello  apple '.translate(str.maketrans('', '', ' \n\t\r'))

OR if you want to be thorough:

import string
' hello  apple'.translate(str.maketrans('', '', string.whitespace))

Python 2

' hello  apple'.translate(None, ' \n\t\r')

OR if you want to be thorough:

import string
' hello  apple'.translate(None, string.whitespace)

ANSWER:

An alternative is to use regular expressions and match these strange white-space characters too. Here are some examples:

Remove ALL spaces in a string, even between words:

import re
sentence = re.sub(r"\s+", "", sentence, flags=re.UNICODE)

Remove spaces in the BEGINNING of a string:

import re
sentence = re.sub(r"^\s+", "", sentence, flags=re.UNICODE)

Remove spaces in the END of a string:

import re
sentence = re.sub(r"\s+$", "", sentence, flags=re.UNICODE)

Remove spaces both in the BEGINNING and in the END of a string:

import re
sentence = re.sub("^\s+|\s+$", "", sentence, flags=re.UNICODE)

Remove ONLY DUPLICATE spaces:

import re
sentence = " ".join(re.split("\s+", sentence, flags=re.UNICODE))

(All examples work in both Python 2 and Python 3)