From 1bb06dee9fb5ecc53ea38af68bf053cc35e7b1be Mon Sep 17 00:00:00 2001 From: Neil Smith 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) -- 2.34.1