crypto_analysis.py

import sys
from collections import Counter

english_frequencies = [" ","E","T","A","O","I","N","S","R","H","D","L","U","C","M","F","Y","W","G","P","B","V","K","X","Q","J","Z"]
founds = open(sys.argv[1]).read()
grams = int(sys.argv[2])

#preprocess
founds = founds.replace(" ","")
founds = founds.replace('\n', "")
result=[]
for i in range(grams):
	result.append(Counter())
	for j in range(0,len(founds)):
		result[i].update([founds[j:j+i+1]])
	print("================={}-gramas más frecuentes=================".format(i+1))
	print(result[i].most_common())

plaintext=""
manual_subs = {'S':'E','J':'T','D':'H', 'Q':'A', 'G':'N','W':'D','C':'I','U':'S','N':'R','B':'O','Z':'C','V':'L','M':'U','Y':'P','L':'Y','E':'G','K':'W','F':'K','X':'F', 'T':'M','H':'Q','A':'B','O':'X'}
print("=====Intentando descibrar con las siguientes sustituciones=====")
print(manual_subs)
for i in founds:
	if (i in manual_subs):
		plaintext+=manual_subs[i]
	else:
		plaintext+='*'
print(plaintext)