如何使python接受大小写字母

问题描述

我和我的朋友已经有一段时间像这样的“加密”对话了。该程序的目标是采用加密的消息并将其制成，以便任何人都可以读取它，反之亦然。 但是，如果我使用大写字母，则不会更改它们。 我该如何解决？

VOWELS = ["a","e","i","o","u"]
CONSONANTS = ["b","c","d","f","g","h","j","k","l","m","n","p","q","r","s","t","v","w","x","y","z"]

def encrypt(message: str):
    encryptedMessage = ""
    for letter in message:
        
        if letter in VOWELS:
            newIndex = VOWELS.index(letter) + 1
            if newIndex >= len(VOWELS):
                newIndex = 0
            encryptedMessage += VOWELS[newIndex]

        elif letter in CONSONANTS:
            newIndex = CONSONANTS.index(letter) + 1
            if newIndex >= len(CONSONANTS):
                newIndex = 0
            encryptedMessage += CONSONANTS[newIndex]

        else:
            encryptedMessage += letter

    return encryptedMessage

def decrypt(message: str):
    decryptedMessage = ""
    for letter in message:
        if letter in VOWELS:
            newIndex = VOWELS.index(letter) - 1
            if newIndex >= len(VOWELS):
                newIndex = 0
            decryptedMessage += VOWELS[newIndex]

        elif letter in CONSONANTS:
            newIndex = CONSONANTS.index(letter) - 1
            if newIndex >= len(CONSONANTS):
                newIndex = 0
            decryptedMessage += CONSONANTS[newIndex]

        else:
            decryptedMessage += letter

    return decryptedMessage
    
def better_encryption(message: str,is_encrypt: bool):

    newMessage = ""
    ed = 1 if is_encrypt else -1
    
    for letter in message:
        if letter in VOWELS:
            newIndex = VOWELS.index(letter) + ed 
            if newIndex >= len(VOWELS):
                newIndex = 0
            newMessage += VOWELS[newIndex]

        elif letter in CONSONANTS:
            newIndex = CONSONANTS.index(letter) + ed
            if newIndex >= len(CONSONANTS):
                newIndex = 0
            newMessage += CONSONANTS[newIndex]

        else:
            newMessage += letter

    return newMessage    

def main():

    while True:
        command = str(input("[E]ncrypt or [D]ecrypt? "))

        if "E" in command.upper() :
            print(better_encryption(input("Message: "),True))

        elif "D" in command.upper() :
            print(better_encryption(input("Message: "),False))

        else:
            print("Invalid")

解决方法

在适当的位置使用简单的letter = letter.lower()应该可以满足您的要求：

VOWELS = ["a","e","i","o","u"]
CONSONANTS = ["b","c","d","f","g","h","j","k","l","m","n","p","q","r","s","t","v","w","x","y","z"]

def encrypt(message: str):
    encryptedMessage = ""
    for letter in message:
        letter = letter.lower()
        if letter in VOWELS:
            newIndex = VOWELS.index(letter) + 1
            if newIndex >= len(VOWELS):
                newIndex = 0
            encryptedMessage += VOWELS[newIndex]

        elif letter in CONSONANTS:
            newIndex = CONSONANTS.index(letter) + 1
            if newIndex >= len(CONSONANTS):
                newIndex = 0
            encryptedMessage += CONSONANTS[newIndex]

        else:
            encryptedMessage += letter

    return encryptedMessage

def decrypt(message: str):
    decryptedMessage = ""
    for letter in message:
        letter = letter.lower()
        if letter in VOWELS:
            newIndex = VOWELS.index(letter) - 1
            if newIndex >= len(VOWELS):
                newIndex = 0
            decryptedMessage += VOWELS[newIndex]

        elif letter in CONSONANTS:
            newIndex = CONSONANTS.index(letter) - 1
            if newIndex >= len(CONSONANTS):
                newIndex = 0
            decryptedMessage += CONSONANTS[newIndex]

        else:
            decryptedMessage += letter

    return decryptedMessage
    
def better_encryption(message: str,is_encrypt: bool):

    newMessage = ""
    ed = 1 if is_encrypt else -1
    
    for letter in message:
        letter = letter.lower()
        if letter in VOWELS:
            newIndex = VOWELS.index(letter) + ed 
            if newIndex >= len(VOWELS):
                newIndex = 0
            newMessage += VOWELS[newIndex]

        elif letter in CONSONANTS:
            newIndex = CONSONANTS.index(letter) + ed
            if newIndex >= len(CONSONANTS):
                newIndex = 0
            newMessage += CONSONANTS[newIndex]

        else:
            newMessage += letter

    return newMessage    

def main():

    while True:
        command = str(input("[E]ncrypt or [D]ecrypt? "))

        if "E" in command.upper() :
            print(better_encryption(input("Message: "),True))

        elif "D" in command.upper() :
            print(better_encryption(input("Message: "),False))

        else:
            print("Invalid")

,

我还对您的代码进行了一些改进。
您可以类似地更改encrypt和decrypt。

VOWELS = [ord(c.upper()) for c in ["a","u"]]
CONSONANTS = [ord(c.upper()) for c in ["b","z"]]
# save letters' UPPER_CASE corresponding ascii number

LOWER_CONST = 0x20
UPPER_MASK  = 0xff ^ LOWER_CONST
# we assume all strings are ascii
# in ascii,UPPER_CASE English letters are ORed with 0x20 (32)
# to produce lower_case letters

def better_encryption(message: str,is_encrypt: bool):
    newMessage = ""
    ed = 1 if is_encrypt else -1
    
    for letter in message:
        res = None

        letter = ord(letter) # convert letter to corresponding ascii number
        case = letter & LOWER_CONST # we save letter's sixth bit
        letter &= UPPER_MASK # we set letter's sixth bit to zero,while keeping the other seven bits unchanged

        if letter in VOWELS:
            newIndex = (VOWELS.index(letter) + ed) % len(VOWELS) # mod operation handles cyclic shift
            res = VOWELS[newIndex]

        elif letter in CONSONANTS:
            newIndex = (CONSONANTS.index(letter) + ed) % len(CONSONANTS) # mod operation handles cyclic shift
            res = CONSONANTS[newIndex]

        else:
            res = letter # keep the letter unchanged
        
        res |= case # restore letter's sixth bit
        newMessage += chr(res) # convert res from number to corresponding ascii letter

    return newMessage    

def main():
    while True:
        command = input("[E]ncrypt or [D]ecrypt? ")

        if len(command) == 0: # if user inputs empty string,we may not access the first character
            continue
        
        if command[0].upper() == 'E':
            print(better_encryption(input("Message: "),True)) #encrypt the message

        elif command[0].upper() == 'D':
            print(better_encryption(input("Message: "),False)) #decrypt the message

        else:
            print("Invalid Command")

if __name__ == "__main__":
    main()