我正在制作一种需要向后读取字符串的密码,即使我引用的索引在范围内,我也会得到索引错误:
M = str(input("Input Message: "))
M = M.upper()
L = len(M)
A = ["A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"]
def DECRYPT():
global L
global M
global A
if L%2 != 0:
POS = False
else:
POS = True
i = L-1
NM = ""
while 1:
if M[i] != " ":
INDEX = A.index(M[i])
if POS == True:
INDEX += (i + 1)
else:
INDEX -= (i)
INDEX %= 26
NM = NM+A[INDEX]
i += 1
if POS == True:
POS = False
else:
POS = True
print("\n"+NM)
def ENCRYPT():
global L
global A
global M
POS = True
M = M[::-1]
i = 0
NM = ""
while 1:
if i == L:
break
if M[i] != " ":
INDEX = A.index(M[i])
if POS == True:
INDEX += (i + 1)
else:
INDEX -= (i + 1)
INDEX %= 26
NM = NM+A[INDEX]
i += 1
if POS == True:
POS = False
else:
POS = True
print("\n"+NM)
while 1:
C = int(input("\nWhat do you want to do:\n1) Encrypt Something\n2)Decrypt Something\n\n"))
if C == 1:
ENCRYPT()
if C == 2:
DECRYPT()
其中i是占位符值。我跑了,得到了这个:
Input Message: ABC
What do you want to do:
1) Encrypt Something
2)Decrypt Something
2
Traceback (most recent call last):
File "C:\Users\Danny\Google Drive\SHIFT.py", line 67, in <module>
DECRYPT()
File "C:\Users\Danny\Google Drive\SHIFT.py", line 19, in DECRYPT
if M[i] != " ":
IndexError: string index out of range
我试过改变i的价值无济于事。
答案 0 :(得分:1)
您的代码存在多个问题:正如fernand0所指出的,您的索引运行方式错误;你的POS
的反转发生在代码的不同层面,加密器在每个字符上执行,解密器在每个字母上执行它们 - 它们的工作方式相同;你的六个全球声明中有五个不是必需的;你没有正确处理断字,所以解密不符合原件;加密后,无法在同一会话中解密,因为本地NM
没有反馈到全局M
。
以下是我对代码的修改,解决了上述问题和一些样式问题。这里的关键词是&#39;简化&#39;。我保留了你奇怪的大写变量名称,但是将它们从单个字符扩展到它们所代表的内容:
MESSAGE = input("Input Message: ").upper()
ALPHABET = list("ABCDEFGHIJKLMNOPQRSTUVWXYZ")
ALPHABET_LENGTH = len(ALPHABET)
def DECRYPT(MESSAGE):
LENGTH = len(MESSAGE)
IS_NEGATIVE = True
NEW_MESSAGE = ""
for I in range(LENGTH):
if MESSAGE[I] in ALPHABET:
INDEX = ALPHABET.index(MESSAGE[I])
if IS_NEGATIVE:
INDEX -= (I + 1)
else:
INDEX += (I + 1)
INDEX %= ALPHABET_LENGTH
NEW_MESSAGE += ALPHABET[INDEX]
IS_NEGATIVE = not IS_NEGATIVE
else:
NEW_MESSAGE += MESSAGE[I]
return NEW_MESSAGE[::-1]
def ENCRYPT(MESSAGE):
MESSAGE = MESSAGE[::-1]
LENGTH = len(MESSAGE)
IS_POSITIVE = True
NEW_MESSAGE = ""
for I in range(LENGTH):
if MESSAGE[I] in ALPHABET:
INDEX = ALPHABET.index(MESSAGE[I])
if IS_POSITIVE:
INDEX += (I + 1)
else:
INDEX -= (I + 1)
INDEX %= ALPHABET_LENGTH
NEW_MESSAGE += ALPHABET[INDEX]
IS_POSITIVE = not IS_POSITIVE
else:
NEW_MESSAGE += MESSAGE[I]
return NEW_MESSAGE
while True:
print("\nWhat do you want to do:")
print("1) Encrypt Message")
print("2) Decrypt Message")
CHOICE = int(input("\n"))
if CHOICE == 1:
MESSAGE = ENCRYPT(MESSAGE)
if CHOICE == 2:
MESSAGE = DECRYPT(MESSAGE)
print("\n" + MESSAGE)
<强> TEST 强>
> python3 file.py
Input Message: An opportunity to teach is an opportunity to learn
What do you want to do:
1) Encrypt Message
2) Decrypt Message
1
OPDAQ HB OEWAGIBFXIU JD RI JZEZZ GC NFVBFJAGWJT KC
What do you want to do:
1) Encrypt Message
2) Decrypt Message
2
AN OPPORTUNITY TO TEACH IS AN OPPORTUNITY TO LEARN
What do you want to do:
1) Encrypt Message
2) Decrypt Message
答案 1 :(得分:0)
你是在字符串末尾开始我然后,你正在增加它。我认为i + = 1行应该是i - = 1