[python] Remove all whitespace in a string

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?

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.

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

>>> import re
>>> re.sub("\s+", # one or more repetition of whitespace
    '', # replace with empty string (->remove)
    ''' hello
...    apple
... ''')
'helloapple'

• https://en.wikipedia.org/wiki/Whitespace_character

Python docs:

• https://docs.python.org/library/stdtypes.html#textseq
• https://docs.python.org/library/stdtypes.html#str.replace
• https://docs.python.org/library/string.html#string.replace
• https://docs.python.org/library/re.html#re.sub
• https://docs.python.org/library/re.html#regular-expression-syntax

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)

' hello  \n\tapple'.translate({ord(c):None for c in ' \n\t\r'})

MaK already pointed out the "translate" method above. And this variation works with Python 3 (see this Q&A).

import re    
sentence = ' hello  apple'
re.sub(' ','',sentence) #helloworld (remove all spaces)
re.sub('  ',' ',sentence) #hello world (remove double spaces)

For removing whitespace from beginning and end, use strip.

>> "  foo bar   ".strip()
"foo bar"

Be careful:

strip does a rstrip and lstrip (removes leading and trailing spaces, tabs, returns and form feeds, but it does not remove them in the middle of the string).

If you only replace spaces and tabs you can end up with hidden CRLFs that appear to match what you are looking for, but are not the same.

In addition, strip has some variations:

Remove spaces in the BEGINNING and END of a string:

sentence= sentence.strip()

Remove spaces in the BEGINNING of a string:

sentence = sentence.lstrip()

Remove spaces in the END of a string:

sentence= sentence.rstrip()

All three string functions strip lstrip, and rstrip can take parameters of the string to strip, with the default being all white space. This can be helpful when you are working with something particular, for example, you could remove only spaces but not newlines:

" 1. Step 1\n".strip(" ")

Or you could remove extra commas when reading in a string list:

"1,2,3,".strip(",")

"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)

try this.. instead of using re i think using split with strip is much better

def my_handle(self):
    sentence = ' hello  apple  '
    ' '.join(x.strip() for x in sentence.split())
#hello apple
    ''.join(x.strip() for x in sentence.split())
#helloapple