How to check for spaces before or after a string in python-CodePudding

How can I find if there are spaces placed before the continuous string I have? For example: 1a2f3adfs3j With this string I want to identify if there are spaces before and after it, then remove them.

CodePudding user response：

If you actually have interest in detecting the presence of these spaces you can check by taking advantage of the ability to slice strings.

s = " abc "
assert(s[0] == " ") # first char
assert(s[-1] == " ") # last char

But there are other ways:

assert(s.startswith(" "))
assert(s.endswith(" "))
# or
first, *_, last = s
assert(first == " ")
assert(last == " ")

You could also check both at the same time:

assert(s[::len(s)-1] == "  ")
# or
assert(s[0]   s[-1] == "  ")

Otherwise, as others pointed out. str.strip is likely what you're after. It will remove leading and trailing whitespace, but leave any within the text.

CodePudding user response：

try this

var = "   abc   "

var.strip()

CodePudding user response：

To actually see if you have spaces, you could use:

s = " abcd1234 "
print(s[0] == " ", s[-1] == " ")

Or another way is to see if it startswith or endswith a space:

print(s.startswith(" "), s.endswith(" "))

To remove the spaces:

s = s.strip()

should do and remove the spaces and assign it to s.

CodePudding user response：

What about

>>> var = ' 1a2f3adfs3j '
>>> var == f' {var[1:-1]} '
True

which approach is not space-specific. e.g

>>> var = '__1a2f3adfs3j__'
>>> var == f'__{var[2:-2]}__'
True