Rotting substitution cipher examples

rot-dict.py

# -*- encoding: utf-8 -*-


def circle_alphabet(offset='a', start='a'):
    start_code = ord(start)
    offset_code = ord(offset)
    for i in range(offset_code, start_code + 26):
        yield chr(i)
    for i in range(start_code, offset_code):
        yield chr(i)


class Rotter(object):
    def __init__(self, n=13):
        self.map = None
        self.n = n
        self._make_table()

    def _make_table(self):
        pivot = chr(ord('a') + self.n)
        self.map = dict(
            zip(circle_alphabet('a'), circle_alphabet(pivot))
        )
        self.map.update(dict(
            zip(circle_alphabet('A', 'A'), circle_alphabet(pivot.upper(), 'A'))
        ))

    def rot(self, s):
        return ''.join(self.map.get(c, c) for c in s)


if __name__ == '__main__':
    print(Rotter().rot('Sbe pbecbengr erny rfgngr naq snpvyvgvrf znantrzrag, genqvgvbany ohvyqvat pbageby flfgrzf ner '
                       'zbivat gb gur VbG naq pbtavgvir cyngsbezf.'))
    print(Rotter(2).rot('abcdeABCDE'))

rot-index.py

# -*- encoding: utf-8 -*-
import string


def rotc(c, n=13):
    if c in string.ascii_lowercase:
        s = 'a'
    elif c in string.ascii_uppercase:
        s = 'A'
    else:
        return c
    o = ord
    return chr( ( o(c) - o(s) + n ) % 26 + o(s) )


def rot(s, n=13):
    return ''.join(map(lambda c: rotc(c, n), s))


if __name__ == '__main__':
    print(rot('Sbe pbecbengr erny rfgngr naq snpvyvgvrf znantrzrag, genqvgvbany ohvyqvat pbageby flfgrzf ner zbivat '
              'gb gur VbG naq pbtavgvir cyngsbezf.')) 
    print(rot('abcdeABCDE', 2))

rot-translate.py

# -*- encoding: utf-8 -*-


def circle_alphabet(offset='a', start='a'):
    start_code = ord(start)
    offset_code = ord(offset)
    for i in range(offset_code, start_code + 26):
        yield chr(i)
    for i in range(start_code, offset_code):
        yield chr(i)


def rot(s, n=13):
    pivot = chr(ord('a') + n)
    table = str.maketrans(
        ''.join(circle_alphabet()) + ''.join(circle_alphabet('A', 'A')),
        ''.join(circle_alphabet(pivot)) + ''.join(circle_alphabet(pivot.upper(), start='A')),
    )
    return s.translate(table)


if __name__ == '__main__':
    print(rot('Sbe pbecbengr erny rfgngr naq snpvyvgvrf znantrzrag, genqvgvbany ohvyqvat pbageby flfgrzf ner zbivat gb gur '
        'VbG naq pbtavgvir cyngsbezf.'))
    print(rot('abcdeABCDE', 2))