class Solution:
def isValid(self, s: str) -> bool:
stack = []
paranthesis_exp = {
"}" : "{",
"]" : "[",
")" : "("
}
for char in s:
if char in paranthesis_exp.values():
stack.append(char)
elif char in paranthesis_exp.keys():
if not stack or stack[-1] != paranthesis_exp[char]:
return False
stack.pop()
return len(stack) == 0