DSA-Stack-Python- Valid Parenthesis

[jen-sjen]

Hey there, I'm participating in #hactoberfest2k21, Please assign me the issue. Good day!
Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.
An input string is valid if:
Open brackets must be closed by the same type of brackets.
Open brackets must be closed in the correct order.
Example:
Input: s = "()[]{}"
Output: true

[ramnagane99]

you have to check small mistakes

[jen-sjen]

As in?

[jen-sjen]

@ishangoyal13
Please merge my previous PR: #115 , issue: #56
So that I can go ahead with this PR :)