How can I do this PYTHON ONLY

Write a function that given a string (argument), containing only the characters (),,{},,[ and ], determine if the input string is valid (return otherwise An input string is valid if: 1. The string only contains (),,{},,[ or characters. 2. All open brackets are closed. 3. Open brackets must be closed by the same type of brackets. 4. Open brackets must be closed in the correct order/type. Tips - You can use a list (i.e. to help you verify the order of opening/closing brackets - When you find an opening bracket, you can add it to the using - When you find a closing bracket you the last element from - if that is the opening pair, then it's correct -- you can proceed - if not, then the string is invalid