caesar cipher Simple Encryption code in python

Question

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Caesar's Cipher using python, could use a little help

def affine (a, b):
    for i in range(26):
        print chr(i+65) + ": " + chr (((a*i+b)%26)+65)

This is something I have come across. How can I use this with a message "Hello world" and encrypt it?

And also how to Decrypt a message?

well sorry mate i today only kept my hands on python and my lecturer want me to learn this by the end of the day — Loshan Wickramasekara, Jan 12 '12 at 05:18

jsbueno · Answer 1 · 2012-01-12T05:18:00.220

0

A readable, though extense, way of doing it is this:

   def encript(message, offset):
       result = ""
       for letter in message:
           if letter.isalpha():
               new_letter = chr(ord(letter) + offset)
               if (new_letter > "Z" and letter.isupper()) or (new_letter > "z" and letter.islower()):
                    new_letter = chr(ord(new_letter) - 26)
           else:
               new_letter = letter
           result += new_letter
        return result

a one liner version could be written thus:

>>> encript = lambda x, offset: "".join(chr(ord(le) + ((offset - (26 if (ord(le.upper()) + offset > ord("Z") )  else 0 ) ) if le.isalpha() else 0))  for le in x )
>>> encript("IBM 9000", -1)
'HAL 9000'

edited Jan 12 '12 at 05:18

answered Jan 12 '12 at 05:10

jsbueno

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File "", line 11 return result ^ IndentationError: unindent does not match any outer indentation level this error is coming for me..... – Loshan Wickramasekara Jan 12 '12 at 05:18
hey can u please tell me y am i getting the error as above – Loshan Wickramasekara Jan 12 '12 at 05:39
1

Did you actually listen to anything you were told about the language so far? Read any reference material? Try writing any code? Putting in any effort at all? – Karl Knechtel Jan 12 '12 at 08:10

caesar cipher Simple Encryption code in python

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