def rotate(n,xs):
    return xs[0:len(xs)-n] + xs[len(xs)-n:]


Some Notes on Cipher Program


n = 4
xs =   [1,2,        3,4,5,6]  
[3,4,5,6,      1,2]



n = 6
xs = [1,2,3,4,     5,6,7,8,9,10]

where should I slice the original list?
at this index: len(xs)-n


xs[0:len(xs)-n]

len(xs) = 6
n = 4
2

xs[len(xs)-n]

xs[0:len(xs)-n] + xs[len(xs)-n:]



es = table_from_corpus()
os = frequencies(s)

chisqr(rotate(0,os),es) = 26.92
chisqr(rotate(1,os),es) = 100.22
...

chisqr(rotate(9,os),es) = 8.2
...
chisqr(rotate(25,os),es) = 92.22

                           0          1               ?            25
similarity_list = [26.92,100.22, ..., 8.2, ..., 92.22]
m = 8.2


def crack(s):
  # input s is the encoded text
  es = table_from_corpus()
  os = frequencies(s)
  similarity_list = chisquare_statistic(os,es)  
  m = min(similarity_list)
  shift = similarity_list.index(m)
  return encode(-shift,s)
  
  
  [ (2,'Red'),  (3,'Blue'),  (1,'Green') ]
  
 result =  [(1,'Green'), (2,'Red'), (3,'Blue'), (3,'Purple')]
  max_vote = result[-1][0]
  
  [('Red',2),   ()]
  
  
  
  f(x) = x*x
  
  answer = f(5)