def substitute(text,right_key,left_key,decipher):
#Get the mappings for polybius squares and their inverse
#The inverse is for lookups.
plain_table,in_plain = get_polybius(inverse_map=True)
right_table,in_right = get_polybius(key=right_key,
inverse_map=True)
left_table,in_left = get_polybius(key=left_key,
inverse_map=True)
#Get the digrams for the text as a list of tuples.
text = get_digrams(list(text),allow_doubles=True)
out_text = []
for i in text:
if not decipher:
a_coords = plain_table[i[0]]
b_coords = plain_table[i[1]]
out_text.append(in_right[(a_coords[0],b_coords[1])])
out_text.append(in_left[(b_coords[0],a_coords[1])])
else:
a_coords = right_table[i[0]]
b_coords = left_table[i[1]]
out_text.append(in_plain[(a_coords[0],b_coords[1])])
out_text.append(in_plain[(b_coords[0],a_coords[1])])
return ''.join(out_text).upper()
def create_cipher(args):
"""
Cipher things in a specified way.
"""
if args.text:
text = args.text
elif args.file:
text = open(args.file).read()
digrams = get_digrams(list(text),'x')
out_text = []
table = get_polybius(key=args.pass_phrase)
#Creates an inverse table for lookups
in_table = {}
for i in table:
in_table[table[i]] = i
for i in digrams:
out_text += get_new_digram(i,table,in_table,args.decipher)
return ''.join(out_text)
