如何在Python中删除前导空格？

I have a text string that starts with a number of spaces, varying between 2 & 4.

What is the simplest way to remove the leading whitespace? (ie. remove everything before a certain character?)

"  Example"   -> "Example"
"  Example  " -> "Example  "
"    Example" -> "Example"

The lstrip() method will remove leading whitespaces, newline and tab characters on a string beginning:

>>> '     hello world!'.lstrip()
'hello world!'

Edit

As balpha pointed out in the comments, in order to remove only spaces from the beginning of the string, lstrip(' ') should be used:

>>> '   hello world with 2 spaces and a tab!'.lstrip(' ')
'\thello world with 2 spaces and a tab!'

Related question:

• Trimming a string in Python

The function strip will remove whitespace from the beginning and end of a string.

my_str = "   text "
my_str = my_str.strip()

will set my_str to "text".

If you want to cut the whitespaces before and behind the word, but keep the middle ones.
You could use:

word = '  Hello World  '
stripped = word.strip()
print(stripped)

To remove everything before a certain character, use a regular expression:

re.sub(r'^[^a]*', '')

to remove everything up to the first ‘a’. [^a] can be replaced with any character class you like, such as word characters.

The question doesn’t address multiline strings, but here is how you would strip leading whitespace from a multiline string using python’s standard library textwrap module. If we had a string like:

s = """
    line 1 has 4 leading spaces
    line 2 has 4 leading spaces
    line 3 has 4 leading spaces
"""

if we print(s) we would get output like:

>>> print(s)
    this has 4 leading spaces 1
    this has 4 leading spaces 2
    this has 4 leading spaces 3

and if we used textwrap.dedent:

>>> import textwrap
>>> print(textwrap.dedent(s))
this has 4 leading spaces 1
this has 4 leading spaces 2
this has 4 leading spaces 3