Custom String to Integer

atoi.py

import math


def atoi(s):
    
    return "".join(map(lambda x: str(ord(x)), s))

print [ord(str(i)) for i in range(1,10)]


print ord("+")

def myAtoi(s):
        """
        :type str: str
        :rtype: int
        """
       if len(s) == 0:
            return 0
        possibles = []
        
        sign = False
        spaceEnd = False
        for i in s:
            ordinal = ord(i)
            #print i, ordinal
            if 57 >= ordinal >= 48:
                spaceEnd = True
                possibles.append(i)
            elif ordinal in [32] :
                if spaceEnd:
                    break
                pass
            elif ordinal == 43:
                spaceEnd=True
                if sign:
                    return 0
                else:
                    sign = True
            elif ordinal == 45:
                spaceEnd=True
                if sign:
                    return 0
                sign = True
                possibles.append(i)
            else:
                break
            #elif ordinal == 
        try:
            res = int("".join(possibles))
            if res > 2147483647:
                return 2147483647
            elif res < -2147483648:
                return -2147483648
            else:
                return res
        except ValueError:
            return 0
    
    
print myAtoi("    -0012ab56")
print myAtoi("123 456")
print myAtoi("    -123")