How to "hide" curse words in a py file?

Question

I'm a school teacher who spent the summer writing a vocab training program in python that uses text available from wikipedia and gutenberg. Now all I have to do is figure out a way to filter out curse words so that I can distribute to students.

Normally I would just have an array (list) of those curse words and do a simple filter. The problem though is that the py file itself it openable by these students, seeing those words. If I put it in a separate file, somehow encrypted, then they could just delete that file and the output wouldn't be filtered.

Any ideas for workarounds?

Answer 1

What you could do is hash the words you want to search for. It makes the filtering a little harder, since you must break the input into words, hash each word, then see if you have a match for that hash.

Take a look a the documentation for md5()

Your source code will then just contain hashed words, and there is no way to reverse that into a list of words (however, the more creative student might have a few sound guesses!)

Answer 2

If all the students are running the same version of Python (e.g. at a computer lab), you can distribute pyc files. This is just obfuscation, but it will deter casual users.

Answer 3

Include the words in your distributed file, but encrypt them somehow to make it impossible to easily find the plaintext list. Then, compile the script to .exe using py2exe. This will stop most students from reverse-engineering the program and finding the encrypting algorithm.

If a student finds the decryption routine, it doesn't matters if it's a strong encryption or not, so rot13 or base64 should be enough.

(w.decode('rot13') for w in ['sbeovqqra', 'sbeovqqra gbb', 'rira zber sbeovqqra'])

For making the list, just use encode on the real words.

Hashes, like suggested above, will work too, of course.

Answer 4

Why not distribute the compiled python .*pyc files instead? They could still lookup the strings if they wanted, but it will likely deter casual browsing of the file, which may be sufficient for your needs.

Answer 5

def avoid_paperwork(word):
    result = ''
    for letter in word:
        if letter == 'z':
            result += '_'
        else:
            result += chr(ord(letter) + 1)
    return result