From 1bb06dee9fb5ecc53ea38af68bf053cc35e7b1be Mon Sep 17 00:00:00 2001
From: Neil Smith <neil.git@njae.me.uk>
Date: Mon, 18 Nov 2013 15:17:46 +0000
Subject: [PATCH] Used a list comprehension in transpositions_of, refactored
column transposition en-/de- cipher
---
cipher.py | 25 +++++++++++++++++--------
1 file changed, 17 insertions(+), 8 deletions(-)
diff --git a/cipher.py b/cipher.py
index 7d3ba78..40e771f 100644
--- a/cipher.py
+++ b/cipher.py
@@ -424,10 +424,8 @@ def transpositions_of(keyword):
>>> transpositions_of('clever')
[0, 2, 1, 4, 3]
"""
- transpositions = []
key = deduplicate(keyword)
- for l in sorted(key):
- transpositions += [key.index(l)]
+ transpositions = [key.index(l) for l in sorted(key)]
return transpositions
def column_transposition_encipher(message, keyword):
@@ -435,19 +433,30 @@ def column_transposition_encipher(message, keyword):
>>> column_transposition_encipher('hellothere', 'clever')
'hleolteher'
"""
- transpositions = transpositions_of(keyword)
- columns = every_nth(message, len(transpositions), fillvalue=' ')
- transposed_columns = transpose(columns, transpositions)
- return combine_every_nth(transposed_columns)
+ return column_transposition_worker(message, keyword, True)
def column_transposition_decipher(message, keyword):
"""
>>> column_transposition_decipher('hleolteher', 'clever')
'hellothere'
"""
+ return column_transposition_worker(message, keyword, False)
+
+def column_transposition_worker(message, keyword, encipher=True):
+ """
+ >>> column_transposition_worker('hellothere', 'clever')
+ 'hleolteher'
+ >>> column_transposition_worker('hellothere', 'clever', True)
+ 'hleolteher'
+ >>> column_transposition_worker('hleolteher', 'clever', False)
+ 'hellothere'
+ """
transpositions = transpositions_of(keyword)
columns = every_nth(message, len(transpositions), fillvalue=' ')
- transposed_columns = untranspose(columns, transpositions)
+ if encipher:
+ transposed_columns = transpose(columns, transpositions)
+ else:
+ transposed_columns = untranspose(columns, transpositions)
return combine_every_nth(transposed_columns)
--
2.43.0