crypt_io

crypto_io is a text interface showcasing the various cyphers you have written in Game Plan. Both encrypting and decrypting messages are supported. Encrypted messages are automatically saved to a msgs folder; messages to decrypt can be selected from this folder or typed manually.

Setup

First, save a copy of crypto_io.py in the same folder as the cyphers you have written.

Next, create a new subfolder named \msgs. This is where encrypted messages are stored and fetched from.

Then, refactor the import calls on lines 6-9 to refer to your files and function definitions. Take line 6 for example:

from YOUR_SHIFT_CYPHER_FILE import YOUR_SHIFT_DEF as shift_cypher

If your shift cypher is named CeaserCypher.py, and your encode function definition in that file is def encode(message):, you would rewrite line 6 to:

from CeaserCypher import encode as shift_cypher`

Note the .py extension on the file name is not included.

Line 6 now imports the encode function definition into crypto_io, and renames it as shift_cypher. Throughout crypto_io, all cypher functions are referred to by the names defined on lines 6-9; if you want to keep your original function names, or rename them to something else, you'll have to change every reference throughout crypto_io -- and be sure to avoid collisions.

A Note On Import & Function Definitions

Not all of the cyphers in Game Plan are set up to use function calls; some of them simply run the code, top to bottom. For these projects, obviously we can't import a function that hasn't been defined, so you'll need to refactor the cypher. Additionally, importing a file runs all the code in that file; in the case of function definitions, they are merely stored in memory; in the case of function calls, they'll be actually executed, and clutter up our user interface. So we have two reasons to refactor our earlier cyphers from linear programs to modular, function-based programs: to import those functions, and to remove clutter.

Any code related to the functionality of the cypher should be moved into a new function defintion. Make sure that function returns a value, instead of printing it.

Any code related to demoing the cypher with a hardcoded string, or by taking user input, should be moved into a main() function definition. To maintain the ability of the cypher to run independently of crypto_io, also include these two lines at the end of your file:

if __name__ == "__main__":
    main()

__name__ is a special variable set by the Python environment at runtime. If the script is being run directly, __name__ is set to __main__; if the script is being imported, __name__ is set to the name of the script (aka module). With the above two lines, the cypher can run independently with the original input method, or can be called from crypto_io.