Python-сообщество

>>> def tr(c):
...     lower = 'abcdefghijklmnopqrstuvwxyz'
...     if c in lower:
...         return lower[(lower.index(c) + 2) % len(lower)]
...     else:
...         return c
... 
>>> s = ('g fmnc wms bgblr rpylqjyrc gr zw fylb. rfyrq '
...      'ufyr amknsrcpq ypc dmp. bmgle gr gl zw fylb gq '
...      'glcddgagclr ylb rfyr\'q ufw rfgq rcvr gq qm jmle. '
...      'sqgle qrpgle.kyicrpylq() gq pcamkkclbcb. lmu '
...      'ynnjw ml rfc spj.')
>>> 
>>> out = ''.join(map(tr, s))
>>> out
"i hope you didnt translate it by hand. thats what computers are for. doing it in by hand is inefficient and that's why this text is so long. using string.maketrans() is recommended. now apply on the url."
>>>

from collections import deque 
from string import lowercase
_aux = deque(lowercase)
_aux.rotate(-2)  # "круговой" сдвиг алфавита на 2 буквы!!!
transform = {a:b for a, b in zip(lowercase, _aux)}
yourstring = '''g fmnc wms bgblr rpylqjyrc gr zw fylb. rfyrq ufyr amknsrcpq ypc dmp. bmgle gr gl zw fylb gq glcddgagclr ylb rfyr'q ufw rfgq rcvr gq qm jmle. sqgle qrpgle.kyicrpylq() gq pcamkkclbcb. lmu ynnjw ml rfc spj.'''
result = ''.join(map(lambda x: transform[x] if x in transform else x, yourstring))
print result

>>> s = ('g fmnc wms bgblr rpylqjyrc gr zw fylb. rfyrq '
...      'ufyr amknsrcpq ypc dmp. bmgle gr gl zw fylb gq '
...      'glcddgagclr ylb rfyr\'q ufw rfgq rcvr gq qm jmle. '
...      'sqgle qrpgle.kyicrpylq() gq pcamkkclbcb. lmu '
...      'ynnjw ml rfc spj.')
>>> 
>>> s.translate(str.maketrans('abcdefghijklmnopqrstuvwxyz',
...                           'cdefghijklmnopqrstuvwxyzab'))
"i hope you didnt translate it by hand. thats what computers are for. doing it in by hand is inefficient and that's why this text is so long. using string.maketrans() is recommended. now apply on the url."
>>>