How do I trim whitespace from a string?

How do I remove leading and trailing whitespace from a string in Python?

For example:

" Hello " --> "Hello"
" Hello"  --> "Hello"
"Hello "  --> "Hello"
"Bob has a cat" --> "Bob has a cat"

Just one space or all consecutive spaces? If the second, then strings already have a .strip() method:

>>> ' Hello '.strip()
'Hello'
>>> ' Hello'.strip()
'Hello'
>>> 'Bob has a cat'.strip()
'Bob has a cat'
>>> '   Hello   '.strip()  # ALL consecutive spaces at both ends removed
'Hello'

If you only need to remove one space however, you could do it with:

def strip_one_space(s):
    if s.endswith(" "): s = s[:-1]
    if s.startswith(" "): s = s[1:]
    return s

>>> strip_one_space("   Hello ")
'  Hello'

Also, note that str.strip() removes other whitespace characters as well (e.g. tabs and newlines). To remove only spaces, you can specify the character to remove as an argument to strip, i.e.:

>>> "  Hello\n".strip(" ")
'Hello\n'

As pointed out in answers above

my_string.strip()

will remove all the leading and trailing whitespace characters such as \n, \r, \t, \f, space .

For more flexibility use the following

• Removes only leading whitespace chars: my_string.lstrip()
• Removes only trailing whitespace chars: my_string.rstrip()
• Removes specific whitespace chars: my_string.strip('\n') or my_string.lstrip('\n\r') or my_string.rstrip('\n\t') and so on.

More details are available in the docs.

strip is not limited to whitespace characters either:

# remove all leading/trailing commas, periods and hyphens
title = title.strip(',.-')

This will remove all leading and trailing whitespace in myString:

myString.strip()

You want strip():

myphrases = [" Hello ", " Hello", "Hello ", "Bob has a cat"]

for phrase in myphrases:
    print(phrase.strip())