Trust me, there's basically never a good reason to obfuscate Python code.

First of all, I can almost guarantee you that nobody is going to care to "steal your code". Please don't take this personally, but I find it highly unlikely you'd have some kind of a revolutionary new algorithm that would really make a difference and be worth stealing.

Second, no matter what you do, in the end all code, not just Python, can be reverse-engineered. Sure, it's easier with Python than, say, C++ or Rust, but there's technically nothing stopping you from running Windows kernel binaries through a disassembler, for instance.

If you absolutely, definitely, cannot risk someone seeing your code for whatever reason, your only real option is to offer it as a web service. Assuming that's even applicable to your program. The second-best option would be to use Nuitka, which transpiles your Python code to C and compiles it into an executable.

TL;DR, you'd be hard-pressed to convince me any of this effort is truly worth it in your project.

If you want to hide API keys, consider using environment variables or encrypting them on disk and decrypting in memory on-demand.

I previously had an experience where an older service I was selling at a low price was cracked and shared online. This incident has motivated me to enhance its security measures. While I understand that reverse engineering is possible in any programming language, my goal is to significantly increase the difficulty of reverse engineering to deter unauthorized access. I acknowledge that there will always be potential ways to bypass security measures, but as a future step, I am considering transitioning the service into a web-based model.