Question

File Encryption and Decryption

chapter 9 programming exercise #3

Design and write a python program to successfully complete chapter 9 programming exercise #3.

File Encryption and Decryption

Write a program that uses a dictionary to assign “codes” to each letter of the alphabet. For example:

codes = { ‘A’ : ‘%’, ‘a’ : ‘9’, ‘B’ : ‘@’, ‘b’ : ‘#’, etc . . .}

Using this example, the letter A would be assigned the symbol %, the letter a would be assigned the number 9, the letter B would be assigned the symbol @, and so forth.

The program should open a specified text file, read its contents, then use the dictionary to write an encrypted version of the file’s contents to a second file. Each character in the second file should contain the code for the corresponding character in the first file.

Write a second program that opens an encrypted file and displays its decrypted contents on the screen.

Answer 1

****This requires some effort so please drop a like if you are satisfied with the solution*****

I have taken a sample text and providing screenshots of execution and files created so please go through them for reference and better understanding..

encryptor.py:

import os.path
Path="C://Users/THE__INFINITY/Desktop"
sampleFilePath=os.path.join(Path,"sample.txt")
encryptionFilePath=os.path.join(Path,"excryption.txt")

f=open(encryptionFilePath,'w+')
s=open(sampleFilePath,'r')

samplecontent=s.read()

letterdict={'h':'%','a':'!','p':'#','y':'$',' ':'^','c':'&','e':'*','g':'(','i':')','n':'-','1':',','2':'+','3':'`'}
for i in range(len(samplecontent)):
    f.write(letterdict[samplecontent[i]])
f.close()
s.close()

decryption.py:

import os.path
Path="C://Users/THE__INFINITY/Desktop"
encryptionFilePath=os.path.join(Path,"excryption.txt")
decryptionFilePath=os.path.join(Path,"decryption.txt")

e=open(encryptionFilePath,'r')
d=open(decryptionFilePath,'w+')
encryptedContent=e.read()
letterdict={'%':'h','!':'a','#':'p','$':'y','^':' ','&':'c','*':'e','(':'g',')':'i','-':'n',',':'1','+':'2','`':'3'}

for i in range(len(encryptedContent)):
    d.write(letterdict[encryptedContent[i]])

e.close()
d.close()