def getBest(possKeys, ciph):
"""Find best mapping in given possibilities."""
results = []
for key in possKeys:
keyMap = dict(zip(ALPH, key))
result = sub(ciph, keyMap)
results.append((key, DetectEnglish.detect(result),
-DetectEnglish.chiSquared(result)))
best = max(results)
bestMap = dict(zip(ALPH, best[0]))
result = sub(ciph, bestMap)
return result, best[1], bestMap
def decrypt(ciph):
"""Try every possible shift and choose the best result."""
bestScore = 9e99
bestKey = ""
bestResult = ""
for i in range(26):
result = shift(ciph, i)
score = DetectEnglish.chiSquared(result)
if score < bestScore:
bestScore = score
bestResult = result
bestKey = ALPH[i]
return bestResult, bestKey