Takes a string and encodes it using a simple cipher.
Python, 49 lines
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Copy to clipboard1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 | """
A program for coding and decoding messages
"""
SHIFT = 1
def shift_coder(str):
"""
Takes a string and codes it
"""
characters = list(str)
coded_characters = []
for dummy_char in characters:
ascii_int = ord(dummy_char)
if ascii_int in range(32) + range(32, 65) + range(91, 97) + \
range(123, 128):
new_char = chr(ascii_int)
elif ascii_int in range(65, 91):
new_char = chr(((ord(dummy_char) + SHIFT - 65) % 26) + 65)
elif ascii_int in range(97, 123):
new_char = chr(((ord(dummy_char) + SHIFT - 97) % 26) + 97)
coded_characters.append(new_char)
coded_str = "".join(coded_characters)
return coded_str
def shift_decoder(str):
"""
Takes a coded string and decodes it into the original message
"""
characters = list(str)
coded_characters = []
for dummy_char in characters:
ascii_int = ord(dummy_char)
if ascii_int in range(32) + range(32, 65) + range(91, 97) + \
range(123, 128):
new_char = chr(ascii_int)
elif ascii_int in range(65, 91):
new_char = chr(((ord(dummy_char) - SHIFT - 65) % 26) + 65)
elif ascii_int in range(97, 123):
new_char = chr(((ord(dummy_char) - SHIFT - 97) % 26) + 97)
coded_characters.append(new_char)
coded_str = "".join(coded_characters)
return coded_str
|
Depending on the value of SHIFT variable, characters in a string are switched. E.g. if SHIFT = 1:
a becomes b, b becomes c, ..., z becomes a
Utilizes ASCII integer values to do the actual coding. Punctuation stays the same, as do lower/upper cases. Also contains a decoder. Give the code to a friend and keep all your messages a secret! (or something like that...)
This program could actually be shortened into just one function if a second argument is given, indicating whether to "code" or "decode". The only difference between the functions is whether to add or subtract the SHIFT value (+ == "code", - == "decode").