Effect of del on Unused Parameters in Jitted JAX Functions

[helpingstar]

Hello,

Thank you very much for always providing kind explanations to many questions. While studying the optax code, I noticed the following pattern: when a function is designed to have consistent parameter signatures for practical purposes, unused parameters are immediately deleted using del, assuming that these parameters are obviously not needed.

In the example below, it is del params.

Does this provide any actual benefit in terms of memory usage? I thought that when a function is jitted, unused parameters might be optimized away or the del statement might be ignored (similar to how print is handled).

However, seeing this code pattern used throughout, I am curious whether this actually offers advantages in terms of speed or memory efficiency.

https://github.com/google-deepmind/optax/blob/51b5d419512423408f31a4d8c10803f51fe9e12b/optax/_src/base.py#L223-L240

https://github.com/google-deepmind/optax/blob/51b5d419512423408f31a4d8c10803f51fe9e12b/optax/_src/base.py#L263-L265

[dfm]

I'm not sure this is the right place to open an optax discussion :D, but...

No, this doesn't provide any performance benefits! This pattern is adopted from Google's Python style guide, and it can be useful for making sure that you actually don't use variables, and it can appease the little red squiggles in some editors.

[helpingstar]

Thank you @dfm for the clarification! I appreciate your detailed response. I’ll make sure to ask questions in the appropriate channels in the future. Thanks again for your help!