stacksQueues.py

# Balance Parantheses
def isValid(string):
    balLis = [i for i in string ]
    stack = []
    mapping = {")": "(", "}": "{", "]": "["} # Dictionary
    for i in balLis:
        if i == "(" or i == "[" or i == "{":
            stack.append(i)
        elif i ==")" or i == "]" or i == "}" and len(stack) > 0:
            if stack[-1] == mapping[i]:
                stack.pop()
            else:
                return (False)
        else:
            return (False)
                
    if len(stack) == 0:
        return(True)
    else:
        return (False)
s = "{"
print(isValid(s))