008_String_to_Integer_(atoi).py

class Solution:
    def myAtoi(self, str: str) -> int:
        str = str.strip()
        
        isNegative = False
        if str and str[0] == '-':
            isNegative = True
        if str and (str[0] == '+' or str[0] == '-'):
            str = str[1:]
        if not str:
            return 0
        
        digits = {i for i in '0123456789'}
        result = 0
        
        for c in str:
            if c not in digits:
                break
            result = result * 10 + int(c)
        
        if isNegative:
            result = -result
        
        result = max(min(result, 2**31 - 1), -2**31)
        return result