Mini-Python-Projects/cipher.py at master · nidhi2509/Mini-Python-Projects · GitHub

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""""
File name: cipher.py
Author username(s): jaltarnr, nyaticmb
Date: 10/11/2017
"""
def encode(textfilename, key):
    """This function uses the caeser cipher method to encrypt text inside a file.
    Parameters: textfilename = the name of the file, key = the key you want to use.
    Return value : encoded message"""
    file = open(textfilename,"r")
    c = ""


    count = 0
    countspace = 0
    for line in file:

        for i in range(0, len(line)):

            keyindex= (count + i - countspace) % len(key)
            x = key[keyindex]
            if ord(line[i]) > 96:


                y = ord(line[i]) - 97 + ord(x) - 97

                y = y%26 + 97

                u = chr(y)
                c = c + u
            else:
                c = c + chr(32)
                countspace = countspace + 1
        count = count + len(line)

    return c


def decode(textfilename, key):
    """This function uses the caeser cipher method to decrypt text inside a file.
    Parameters: textfilename = the name of the file, key = the key you want to use.
    Return value : decoded message"""
    file = open(textfilename,"r")
    c = ""


    count = 0
    countspace = 0
    for line in file:

        for i in range(0, len(line)):

            keyindex= (count + i - countspace) % len(key)
            x = key[keyindex]
            if ord(line[i]) > 96:


                y = ord(line[i]) + 97 - ord(x) - 97

                y = y%26 + 97

                u = chr(y)
                c = c + u
            else:
                c = c + chr(32)
                countspace = countspace + 1
        count = count + len(line)

    return c


def encode_space(textfilename, key):
    """This function uses the caeser cipher method to encrypt text inside a file.
    Parameters: textfilename = the name of the file, key = the key you want to use.
    Return value : encoded message"""
    file = open(textfilename,"r")
    c = ""


    count = 0

    for line in file:

        for i in range(0, len(line)):

            keyindex= (count + i ) % len(key)
            x = key[keyindex]

            y = ord(line[i]) - 97 + ord(x) - 97
            y = y%28 + 97
            u = chr(y)
            c = c + u

        count = count + len(line)

    return c
def decode_space(textfilename, key):
    """This function uses the caeser cipher method to decrypt text inside a file.
    Parameters: textfilename = the name of the file, key = the key you want to use.
    Return value : decoded message"""
    file = open(textfilename,"r")
    c = ""


    count = 0
    countspace = 0
    for line in file:

        for i in range(0, len(line)):

            keyindex= (count + i - countspace) % len(key)
            x = key[keyindex]
            y = ord(line[i]) + 97 - ord(x) - 97

            y = y%28 + 97

            u = chr(y)
            c = c + u
        count = count + len(line)

    return c
def main():
    answer = input("Would you like to (e)ncode or (d)ecode?")
    if answer == "e":
        a1 = input("What is your filename?")
        a2 = input("What is your key?")
        print(encode(a1,a2))
    elif answer == "d":
        a1 = input("What is your filename?")
        a2 = input("What is your key?")
        print(decode(a1,a2))
if __name__ == '__main__':
    main()