python playfair加密（如有错误，请留言指正）

import numpy
key_word = str.upper(input('请输入秘钥：'))
key_set = set()
for i in key_word:
    if i.isalpha():
        key_set.add(i)
key_set = list(key_set)
key_set.sort(key=key_word.index)
for i in range(26):
    ch = chr(i+0x41)
    if ch not in key_set:
        key_set.append(ch)
key_set.remove('J')

table = numpy.array(key_set)
table = numpy.reshape(table,(5,5))
model = int(eval(input('请输入填充模式（0：按列，1：按行）：')))
if model == 0:
    table = table.T#by column
else:
    pass
print(r'''密钥矩阵（i/j同位）：
{}'''.format(table))

mes = str.upper(input('请输入明文：'))
M = []
for i in mes:
    if i.isalpha():
        M.append(i)
try:
    M[M.index('J')] = 'I'
except:
    pass

def yjudge(table,ra,ca,rb,cb):
    if ra == rb:
        return 1
    elif ca == cb:
        return 2
    else:
        return 3


i = 0
C = ''
while True:
    len_m = len(M)
    left = len_m - i
    if left == 0:
        break
    elif left == 1:
        M.append('X')
    elif M[i] == M[i+1]:
        M.insert(i+1,'X')
    else:
        pass
    ra,ca = numpy.where(table == M[i])
    ra = ra[0]
    ca = ca[0]
    rb,cb = numpy.where(table == M[i+1])
    rb = rb[0]
    cb = cb[0]
    #print(table[ra,ca],table[rb,cb])
    ytype = yjudge(table,ra,ca,rb,cb)
    #print(ytype)
    if ytype == 1:#同行在右侧
        C = C+table[ra,(ca+1)%5]
        C = C+table[rb,(cb+1)%5]
    elif ytype == 2:#同列在下侧
        C = C+table[(ra+1)%5,ca]
        C = C+table[(rb+1)%5,cb]
    else:#不同行不同列，取同行的那个角
        C = C+table[ra,cb]
        C = C+table[rb,ca]
    i += 2
print(r'''密文：{}'''.format(C))

测试样例（同wikipedia）：

请输入秘钥：playfair example
请输入填充模式（0：按列，1：按行）：1
密钥矩阵（i/j同位）：
[['P' 'L' 'A' 'Y' 'F']
 ['I' 'R' 'E' 'X' 'M']
 ['B' 'C' 'D' 'G' 'H']
 ['K' 'N' 'O' 'Q' 'S']
 ['T' 'U' 'V' 'W' 'Z']]
请输入明文：Hide the gold in the tree stump
密文：BMODZBXDNABEKUDMUIXMMOUVIF