Convert String to int , Such as '123' -> 123

str_to_int.py

def do(in_str):
    out_num = 0
    multiplier = 1
    for x in range(0, len(in_str)):
        out_num = out_num * 10 + ord(in_str[x]) - ord('0')
    return out_num * multiplier

def str_to_int(in_str):
    if '.' in in_str:
        big_num, small_num = in_str.split('.')
        beishu = len(small_num)
        return do(big_num) + do(small_num) / 10 ** beishu
    else:
        return do(in_str)

print(str_to_int('23'), type(str_to_int('23')))
print(str_to_int('23.3'), type(str_to_int('23.3')))
print(str_to_int('23.33'), type(str_to_int('23.33')))
print(str_to_int('23.333'), type(str_to_int('23.333')))
print(str_to_int('6666666'), type(str_to_int('6666666')))

'''
Debug
def to_int(in_str):
    out_num = 0
    multiplier = 1
    for x in range(0, len(in_str)):
    #   0               3
        out_num = out_num * 10 + ord(in_str[x]) - ord('0')
    #      1    =   0     * 10 +        49    -    48
    #      12   =   1     * 10 +        50    -    48
    #      123  =   12    * 10 +        51    -    49
        print(out_num)
    return out_num * multiplier
'''