Check when string contains only special characters in python

Question

So what I want to do is check if the string contains only special characters. An example should make it clear

Hello -> Valid
Hello?? -> Valid
?? -> Not Valid

Same thing done for all special characters including "."

Answer 1

You can use this regex with anchors to check if your input contains only non-word (special) characters:

^\W+$

If underscore also to be treated a special character then use:

^[\W_]+$

RegEx Demo

Code:

>>> def spec(s):
        if not re.match(r'^[_\W]+$', s):
            print('Valid')
        else:
            print('Invalid')


>>> spec('Hello')
Valid
>>> spec('Hello??')
Valid
>>> spec('??')
Invalid

Answer 2

You can use a costume python function :

>>> import string 
>>> def check(s):
...   return all(i in string.punctuation for i in s)

string.punctuation contain all special characters and you can use all function to check if all of the characters are special!