<qiyuangong>020_Valid_Parentheses_1.py
def isValid( s):
    if s is None:
        return True
    stack = []
    for t in s:
        if t == ')':
            try:
                current = stack.pop()
                if current != '(':
                    return False
            except:
                return False
        elif t == '}':
            try:
                current = stack.pop()
                if current != '{':
                    return False
            except:
                return False
        elif t == ']':
            try:
                current = stack.pop()
                if current != '[':
                    return False
            except:
                return False
        else:
            stack.append(t)
    if len(stack) == 0:
        return True
    else:
        return False
def sample_funcname ( var_0 ) :
    if var_0 is None :
        return True
    var_3 = [ ]
    for var_4 in var_0 :
        if var_4 == ')' :
            try :
                var_7 = var_3.pop ( )
                if var_7 != '(' :
                    return False
            except :
                return False
        elif var_4 == '}' :
            try :
                var_7 = var_3.pop ( )
                if var_7 != '{' :
                    return False
            except :
                return False
        elif var_4 == ']' :
            try :
                var_7 = var_3.pop ( )
                if var_7 != '[' :
                    return False
            except :
                return False
        else :
            var_3.append ( var_4 )
    if len ( var_3 ) == 0 :
        return True
    else :
        return False
