Python-在每次while循环重复后写入文本文件的新行

Question

I am trying to save the output of a basic encryption program to a text file. It works, the problem is that it saves each new output right next to the last without a space, or a new line (What I want).

I would like the user to be able to choose a line to read from and decrypt rather than decrypting the whole lot.

Currently I get this-

This program can run three different sub-programs-
1- Run the encryption and decryption sub-program specified in Unit A453- CAM 3.
2- Run a test which encrypts and decrypts each ascii character with each other ascii character.
3- Run a test which generates random inputs and keywords, before encrypting and decrypting them.
Please choose either 1, 2 or 3- 1
Running text based program-
Do you want to encrypt or decrypt? encrypt
Input a key- abc
Input a second key- 123
Input a string to encrypt- Theo
Your encrypted text is %vuA -it has been saved.
Do you wish to continue? Y/N- y
Do you want to encrypt or decrypt? encrypt
Input a key- 123
Input a second key- abc
Input a string to encrypt- Theo
Your encrypted text is %vuA -it has been saved.
Do you wish to continue? Y/N- y
Do you want to encrypt or decrypt? 

So as you can see I have done the same thing twice (Ignore the fact that reversing the encryption keys does nothing- I haven't actually written a proper algorithm for their use, it just adds them on)

The text file looks like this-

%vuA%vuA

I am trying to get it to do this-

%vuA
%vuA

Finally another thing. Not so much a problem but a 'What the hell, why?!' is that the text is not written to the text file until I pick Y or N in the 'do you wish to continue.

The specific bit of code doing the reading and writing is this function-

def User_Text_Interface(Repeat):
    while Repeat == True:
        f = open("COT.txt", "a+")
        ED, Key, Key2, Temp = input("Do you want to encrypt or decrypt? "), input("Input a key- "), input("Input a second key- "), 0
        if ED.lower() =="encrypt" or ED.lower() == "e":
            User_Input =  input("Input a string to " + str(ED) + "- ")
        Key, Key2 = Compatibility(Key, User_Input), Compatibility(Key2,User_Input)
        if ED.lower() == "encrypt" or ED.lower() == "e":
            ET = str(Encrypt((Encrypt(User_Input, Key)), Key2))
            f.write(ET)
            print("Your encrypted text is " + ET + " -it has been saved.")
        elif ED.lower() == "decrypt" or ED.lower() == "d":
            with open("COT.txt", "r+") as f:
                for line in f:
                    print(str(Decrypt((Decrypt((Encrypt((Encrypt(User_Input, Key)), Key2)), Key2)), Key)))
        Repeat = input("Do you wish to continue? Y/N- ")
        if Repeat.lower() == "yes" or Repeat.lower() == "y":
            Repeat = True
        else:
            Repeat = False 

The rest of my code, most of which can be ignored as it is superfluous-

import time, sys, random
Master_Key = "0123456789 abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!\"#£$%&'()*+,-./:;?@[\\]^_`{|}~"

def Encrypt(User_Input, Key):
    Output = ""
    for i in range(len(User_Input)):
        Ref_For_Output = Master_Key.index(User_Input[i]) + Master_Key.index(Key[i]) 
        if Ref_For_Output >= len(Master_Key):     
            Ref_For_Output -= len(Master_Key)
        Output += Master_Key[Ref_For_Output]
    return Output 

def Decrypt(User_Input, Key):
    Output = ""
    for i in range(len(User_Input)):
        Ref_For_Output = Master_Key.index(User_Input[i]) - Master_Key.index(Key[i])
        if Ref_For_Output < 0:
            Ref_For_Output += len(Master_Key)
        Output += Master_Key[Ref_For_Output]
    return Output



def Ordered_Test_Algorithm(Null):
    for i in range(len(Master_Key)-1): 
        Input= Master_Key[i]
        print("Input = " + Input)
        for i in range(len(Master_Key)-1):
            Key = Master_Key[i]
            for i in range(len(Master_Key)-1):
                Key2 = Master_Key[i]
                Output = Decrypt(Encrypt(Input, Key, Key2), Key, Key2)
                print("Encryption and decryption of Input- " + str(Input) + " with the Key- " + str(Key) + " and a second Key of " + str(Key2) + " results in an output of " + str(Output))
                if Input == Output:
                    print("Pass")
                else:
                    print("Fail")
                    sys.exit 
    print("Testing complete- Pass")
def Random_Test_Algorithm(Input_Length, Repeat_times):
    for i in range(Repeat_times): 
        User_Input, Key, Key2 = "", "", ""
        for i in range(Input_Length):
            Input_ref, Key_ref, Key_2_Ref = random.randint(0, len(Master_Key)-1), random.randint(0, (len(Master_Key)-1)), random.randint(0, (len(Master_Key)-1)) 
            User_Input += Master_Key[Input_ref]
            Key += Master_Key[Key_ref]
            Key2 += Master_Key[Key_2_Ref]
        print("The randomly generated " + str(Input_Length) + " character input key and second key are " + User_Input + ", " + Key + " and " + Key2 +" respectively.")
        print("The result of encryption is- " + Encrypt(User_Input, Key, Key2) )
        print("The result of decryption is- " + Decrypt(Encrypt(Input, Key, Key2), Key, Key2) ) 
        if User_Input == Decrypt(Encrypt(Input, Key, Key2), Key, Key2):
            print("The encryption and decryption of " + User_Input + " with " + Key + " and " + Key2 + " was successful")
        else:
            print("The encryption and decryption of " + User_Input + " with " + Key + " and " + Key2 + " was un-successful")
            sys.exit

def Compatibility(Key, User_Input):
    Temp = 0
    while Key == "":
            print("Your key cannot be blank")
    while len(Key) > len(User_Input): 
            Key = Key[:-1]
    while len(Key) < len(User_Input): 
            Key += (Key[Temp]) 
            Temp += 1
    return Key

def User_Text_Interface(Repeat):
    while Repeat == True:
        f = open("COT.txt", "a+")
        ED, Key, Key2, Temp = input("Do you want to encrypt or decrypt? "), input("Input a key- "), input("Input a second key- "), 0
        if ED.lower() =="encrypt" or ED.lower() == "e":
            User_Input =  input("Input a string to " + str(ED) + "- ")
        Key, Key2 = Compatibility(Key, User_Input), Compatibility(Key2,User_Input)
        if ED.lower() == "encrypt" or ED.lower() == "e":
            ET = str(Encrypt((Encrypt(User_Input, Key)), Key2))
            f.write(ET)
            print("Your encrypted text is " + ET + " -it has been saved.")
        elif ED.lower() == "decrypt" or ED.lower() == "d":
            with open("COT.txt", "r+") as f:
                for line in f:
                    print(str(Decrypt((Decrypt((Encrypt((Encrypt(User_Input, Key)), Key2)), Key2)), Key)))
        Repeat = input("Do you wish to continue? Y/N- ")
        if Repeat.lower() == "yes" or Repeat.lower() == "y":
            Repeat = True
        else:
            Repeat = False 

print("This program can run three different sub-programs-")
print("1- Run the encryption and decryption sub-program specified in Unit A453- CAM 3.")
print("2- Run a test which encrypts and decrypts each ascii character with each other ascii character.")
print("3- Run a test which generates random inputs and keywords, before encrypting and decrypting them.")
Option = input("Please choose either 1, 2 or 3- ")
if Option == "1":
    print("Running text based program-")
    time.sleep(1)
    User_Text_Interface(True)
elif Option == "2":
    print("This test will encrypt and decrypt each keyboard character with every other keyboard character")
    print("It will print around 1,860,000 lines of output, unless a decrypted value is not equal to its input, this will cause the test to stop")
    print("Beginning test- ")
    Ordered_Test_Algorithm("Null")
    time.sleep(1)
elif Option == "3":
    print("This test will generate a random input and keyword of a specified length using the random.randint function in the random module.")
    print("It will then encrypt and decrypt the input with the keyword before checking if the output is equal to the input.")
    print("The test will repeat a specifieed number of times.")
    Input_Length = int(input("Input a numerical length (Length in characters e.g. 'Python' is 6 characters)for the key and keyword- "))
    Repeat_times = int(input("Input the number of times the test should be repeated- "))
    print("Beginning test- ")
    time.sleep(1)
    Random_Test_Algorithm(Input_Length, Repeat_times)

Answer 1

In line 77, change

f.write(ET)

to

f.write(ET + "\n")

and at line 88, insert

f.flush()    # force it to write buffered output

(make sure it is indented, inside the while Repeat == True: loop.)

while Repeat == True: is redundant; you can just do while repeat: ; and line 70 ( f = open("COT.txt", "a+") ) can be moved to precede the loop (you only need to open the file once, not once per loop).

and Stop Using InitialCaps For Your Variable Names! :-P

---

Edit :

I just noticed, in Ordered_Test_Algorithm you reuse the index variable i (lines 25, 28, 30); this will not work and will cause you many headaches. Try using a different variable for each for loop!

On line 32, you are trying to call encrypt and decrypt with three arguments; but they are only two-argument functions.

Also, you have a very C++ish coding style; I see a lot of

for i in range(len(Master_Key)-1):  # off-by-1 error; do not subtract 1 from end of range
    Input= Master_Key[i]

where the Pythonic method would be

for ch in Master_Key:

Also, your encrypt and decrypt logic just assumes that len(Key) >= len(User_Input) ; if this is not so, your functions will fail with an IndexError .

Answer 2

I can't take the time to analyze your code, but you should:

1. Open the file in a+ which you have already done.
2. Immediately call myfile.write('\n') after input. 
3. Close the file to press changes.