How do I protect Python code? [closed]

Answer 1

Shipping .pyc files has its problems - they are not compatible with any other python version than the python version they were created with, which means you must know which python version is running on the systems the product will run on. That's a very limiting factor.

Answer 2

Use Cython. It will compile your modules to high-performant C files, which can then be compiled to native binary libraries. This is basically un-reversable, compared to .pyc bytecode!

I've written a detailed article on how to set up Cython for a Python project, check it out:

Protecting Python Sources With Cython

Answer 3

Python is not the tool you need

You must use the right tool to do the right thing, and Python was not designed to be obfuscated. It's the contrary; everything is open or easy to reveal or modify in Python because that's the language's philosophy.

If you want something you can't see through, look for another tool. This is not a bad thing, it is important that several different tools exist for different usages.

Obfuscation is really hard

Even compiled programs can be reverse-engineered so don't think that you can fully protect any code. You can analyze obfuscated PHP, break the flash encryption key, etc. Newer versions of Windows are cracked every time.

Having a legal requirement is a good way to go

You cannot prevent somebody from misusing your code, but you can easily discover if someone does. Therefore, it's just a casual legal issue.

Code protection is overrated

Nowadays, business models tend to go for selling services instead of products. You cannot copy a service, pirate nor steal it. Maybe it's time to consider to go with the flow...

Answer 4

Depending in who the client is, a simple protection mechanism, combined with a sensible license agreement will be far more effective than any complex licensing/encryption/obfuscation system.

The best solution would be selling the code as a service, say by hosting the service, or offering support - although that isn't always practical.

Shipping the code as .pyc files will prevent your protection being foiled by a few #s, but it's hardly effective anti-piracy protection (as if there is such a technology), and at the end of the day, it shouldn't achieve anything that a decent license agreement with the company will.

Concentrate on making your code as nice to use as possible - having happy customers will make your company far more money than preventing some theoretical piracy..

Answer 5

using cxfreeze ( py2exe for linux ) will do the job.

http://cx-freeze.sourceforge.net/

it is available in ubuntu repositories

Answer 6

The best you can do with Python is to obscure things.

• Strip out all docstrings
• Distribute only the .pyc compiled files.
• freeze it
• Obscure your constants inside a class/module so that help(config) doesn't show everything

You may be able to add some additional obscurity by encrypting part of it and decrypting it on the fly and passing it to eval(). But no matter what you do someone can break it.

None of this will stop a determined attacker from disassembling the bytecode or digging through your api with help, dir, etc.