How to strip all whitespace from string

Question

How do I strip all the spaces in a python string? For example, I want a string like strip my spaces to be turned into stripmyspaces, but I cannot seem to accomplish that with strip():

>>> 'strip my spaces'.strip()
'strip my spaces'

Answer 1

Try a regex with re.sub. You can search for all whitespace and replace with an empty string.

\s in your pattern will match whitespace characters - and not just a space (tabs, newlines, etc). You can read more about it in the manual.

Answer 2

The simplest is to use replace:

"foo bar\t".replace(" ", "").replace("\t", "")

Alternatively, use a regular expression:

import re
re.sub(r"\s", "", "foo bar\t")

Answer 3

>>> import re
>>> re.sub(r'\s+', '', 'strip my spaces')
'stripmyspaces'

Also handles any whitespace characters that you're not thinking of (believe me, there are plenty).

Answer 4

Taking advantage of str.split's behavior with no sep parameter:

>>> s = " \t foo \n bar "
>>> "".join(s.split())
'foobar'

If you just want to remove spaces instead of all whitespace:

>>> s.replace(" ", "")
'\tfoo\nbar'

Premature optimization

Even though efficiency isn't the primary goal—writing clear code is—here are some initial timings:

$ python -m timeit '"".join(" \t foo \n bar ".split())'
1000000 loops, best of 3: 1.38 usec per loop
$ python -m timeit -s 'import re' 're.sub(r"\s+", "", " \t foo \n bar ")'
100000 loops, best of 3: 15.6 usec per loop

Note the regex is cached, so it's not as slow as you'd imagine. Compiling it beforehand helps some, but would only matter in practice if you call this many times:

$ python -m timeit -s 'import re; e = re.compile(r"\s+")' 'e.sub("", " \t foo \n bar ")'
100000 loops, best of 3: 7.76 usec per loop

Even though re.sub is 11.3x slower, remember your bottlenecks are assuredly elsewhere. Most programs would not notice the difference between any of these 3 choices.