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How do I trim whitespace?


Question

Is there a Python function that will trim whitespace (spaces and tabs) from a string?

Example: \t example string\texample string

2017/11/10
1
1086
11/10/2017 2:20:28 AM

Accepted Answer

For whitespace on both sides use str.strip:

s = "  \t a string example\t  "
s = s.strip()

For whitespace on the right side use rstrip:

s = s.rstrip()

For whitespace on the left side lstrip:

s = s.lstrip()

As thedz points out, you can provide an argument to strip arbitrary characters to any of these functions like this:

s = s.strip(' \t\n\r')

This will strip any space, \t, \n, or \r characters from the left-hand side, right-hand side, or both sides of the string.

The examples above only remove strings from the left-hand and right-hand sides of strings. If you want to also remove characters from the middle of a string, try re.sub:

import re
print(re.sub('[\s+]', '', s))

That should print out:

astringexample
2020/09/04
1616
9/4/2020 6:47:41 PM

Python trim method is called strip:

str.strip() #trim
str.lstrip() #ltrim
str.rstrip() #rtrim
2015/04/27

For leading and trailing whitespace:

s = '   foo    \t   '
print s.strip() # prints "foo"

Otherwise, a regular expression works:

import re
pat = re.compile(r'\s+')
s = '  \t  foo   \t   bar \t  '
print pat.sub('', s) # prints "foobar"
2017/10/23

You can also use very simple, and basic function: str.replace(), works with the whitespaces and tabs:

>>> whitespaces = "   abcd ef gh ijkl       "
>>> tabs = "        abcde       fgh        ijkl"

>>> print whitespaces.replace(" ", "")
abcdefghijkl
>>> print tabs.replace(" ", "")
abcdefghijkl

Simple and easy.

2014/06/11

#how to trim a multi line string or a file

s=""" line one
\tline two\t
line three """

#line1 starts with a space, #2 starts and ends with a tab, #3 ends with a space.

s1=s.splitlines()
print s1
[' line one', '\tline two\t', 'line three ']

print [i.strip() for i in s1]
['line one', 'line two', 'line three']




#more details:

#we could also have used a forloop from the begining:
for line in s.splitlines():
    line=line.strip()
    process(line)

#we could also be reading a file line by line.. e.g. my_file=open(filename), or with open(filename) as myfile:
for line in my_file:
    line=line.strip()
    process(line)

#moot point: note splitlines() removed the newline characters, we can keep them by passing True:
#although split() will then remove them anyway..
s2=s.splitlines(True)
print s2
[' line one\n', '\tline two\t\n', 'line three ']
2012/02/13

No one has posted these regex solutions yet.

Matching:

>>> import re
>>> p=re.compile('\\s*(.*\\S)?\\s*')

>>> m=p.match('  \t blah ')
>>> m.group(1)
'blah'

>>> m=p.match('  \tbl ah  \t ')
>>> m.group(1)
'bl ah'

>>> m=p.match('  \t  ')
>>> print m.group(1)
None

Searching (you have to handle the "only spaces" input case differently):

>>> p1=re.compile('\\S.*\\S')

>>> m=p1.search('  \tblah  \t ')
>>> m.group()
'blah'

>>> m=p1.search('  \tbl ah  \t ')
>>> m.group()
'bl ah'

>>> m=p1.search('  \t  ')
>>> m.group()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: 'NoneType' object has no attribute 'group'

If you use re.sub, you may remove inner whitespace, which could be undesirable.

2013/02/12

Source: https://stackoverflow.com/questions/1185524
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