14.1 Examples

#This program requires a excellent understanding of decimal numbers
def to_string(in_int):
    "Converts an integer to a string"
    out_str = ""
    prefix = ""
    if in_int < 0:
        prefix = "-"
        in_int = -in_int        
    while in_int / 10 != 0:
        out_str = chr(ord('0')+in_int % 10) + out_str
        in_int = in_int / 10
    out_str = chr(ord('0')+in_int % 10) + out_str
    return prefix + out_str

def to_int(in_str):
    "Converts a string to an integer"
    out_num = 0
    if in_str[0] == "-":
        multiplier = -1
        in_str = in_str[1:]
    else:
        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

print to_string(2)
print to_string(23445)
print to_string(-23445)
print to_int("14234")
print to_int("12345")
print to_int("-3512")
The output is:
2
23445
-23445
14234
12345
-3512