Chapter 9, Problem 3PE

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.