phonebook cs hw you racist cunts

from base64 import b64encode, b64decode
import os
import sys
from getpass import getuser #for salt

class InvalidKey(Exception):
    pass

def encode(key, salt, clear):
    """ Encodes text based on key for security
Creates new variable result, and for each letter in key,
do ord(letter) and add it to result. Once completed,
divide and round the number (/2 and rounded again) by the first half of the number
(for example 1100 would be divided by 11 and rounded"""

    #salt will be used to defend against rainbow tables even though the encoding isnt safe

    result = 0
    for letter in key:
        result+=(ord(letter)) #now result will be something

    #get n amount of characters to get, and set it to divider variable
    divider = int(str(result)[:round(len(str(result)) / 2)])
    keyresult = round(round(result / 2) / divider)
    if keyresult <= 0:
        raise InvalidKey('Key cannot be used, try another')

    #prepare clear for encoding
    clear = bytes(clear, 'utf8')

    for i in range(1,keyresult + 1):
        clear = b64encode(clear)

    return salt + clear.decode('utf8')

def decode(key, salt, clear):
    clear = clear.replace(salt, '') #remove salt
    clear = bytes(clear, 'utf8')

    result = 0
    for letter in key:
        result+=(ord(letter)) #now result will be something

    #get n amount of characters to get, and set it to divider variable
    divider = int(str(result)[:round(len(str(result)) / 2)])
    keyresult = round(round(result / 2) / divider)
    if keyresult <= 0:
        raise InvalidKey('Key cannot be used, try another')

    for i in range(1, keyresult + 1):
        clear = b64decode(clear)

    try:
        b64decode(clear)
        return InvalidKey('Key is not valid')
    except:
        pass

    clear = clear.decode('utf8')
    return clear


"""phonebook format:
firstname,lastname,phonenumber,address"""

def menu():
    print("""
-------------------------------
           PHONEBOOK
-------------------------------
[1] List all numbers
[2] Add a number
[3] Remove a number
[4] Edit a number
[5] Exit""")
    while True:
        inp = input("> ")
        #validate
        if inp == '1':
            with open('phone.book', 'r') as f:
                c = f.read()
            if len(c) == 0:
                print("[+] No phone numbers")
                continue
            decoded = decode(pw, salt, c)
            decoded = decoded.split(':')
            for info in range(len(decoded)):
                decoded[info] = decoded[info].split(',')

            for number in decoded:
                print('---------------')
                print('Firstname: {}'.format(number[0]))
                print('Surname: {}'.format(number[1]))
                print('Number: {}'.format(number[2]))
                print('Address: {}'.format(number[3]))

            print('---------------')
        elif inp == '2':
            firstname = input("Firstname: ").capitalize()
            lastname = input("Surname: ").capitalize()
            number = input("Number: ")
            address = input("Address: ")
            fformat = firstname + ',' + lastname + ',' + number + ',' + address + '\n'
            with open('phone.book', 'a') as f:
                f.write(encode(pw, salt, fformat))
            print("Added {}'s number".format(firstname))
        elif inp == '3':
            with open('phone.book', 'r') as f:
                c = f.read()
            c = decode(pw, salt, c)
            c = c.split(':')
            firstname = input("Firstname: ")
            print("Deleting..\nThis could take long if you have a lot of numbers")
            result = []
            for data in c:
                if data.startswith(firstname):
                    continue
                else:
                    result.append(data)
            result = encode(pw, salt, ':'.join(result))
            with open('phone.book', 'w') as f:
                f.write(result)
            print("Deleted contact.")
        elif inp == '4':
            with open('phone.book', 'r') as f:
                c = f.read()
            c = decode(pw, salt, c)
            c = c.split(':')
            firstname = input("Firstname: ")
            edit = None
            for data in c:
                if data.startswith(firstname):
                    edit = data
                    break
            if edit == None:
                print("Couldn't find anyone called {} in your phonebook.".format(firstname))
                continue
            data = data.split(',')
            print("\nType FINISH to finish")
            print("Syntax: type,new value")
            print("Example: address,7 Something Road")
            while True:
                print('--------------------')
                print('Firstname: {}'.format(data[0]))
                print('Surname: {}'.format(data[1]))
                print('Number: {}'.format(data[2]))
                print('Address: {}'.format(data[3]))
                print('--------------------')
                etype = input("Edit: ")
                if etype == 'FINISH':
                    break
                else:
                    etype = etype.split(',')
                if etype[0]=='firstname':
                    data[0] = etype[1]
                elif etype[0]=='surname':
                    data[1] = etype[1]
                elif etype[0]=='number':
                    data[2] = etype[1]
                elif etype[0]=='address':
                    data[3] = etype[1]
                else:
                    print("Invalid syntax")
        elif inp == '5':
            sys.exit()


def createfile(file):
    """ Creates file by opening with mode w+ and closing"""
    open(file, 'w+').close()

createfile('phone.book')
print("Password should be 5 or less characters")
pw = input("Enter password: ")
salt = getuser()