Working to Make Python Lazy

(iscinumpy.dev)

31 points | by js2 2 days ago

3 comments

  • dataflow 1 hour ago
    > This pattern, for example, can’t be lazy: try: import numpy; except ModuleNotFoundError: ...

    Wait, that seems bad. These kinds of modules (especially numba) are often exactly the ones that you want to delay importing. Why not provide a way to check the existence at import time? How are you supposed to handle nonexistence in that case?

    • zbentley 19 minutes ago
      ...crash?

      Seriously: crash if your dependencies aren't available. There are better ways to do optional dependencies. ImportError ain't it.

      • dataflow 15 minutes ago
        What is the right way to handle an optional dependency?
  • yuriks 56 minutes ago
    This feature seems really valuable for commandline tools! However this paragraph gave me pause:

    > Currently, disabling lazy imports disabled the syntax keyword, which means that you can’t use it for circular imports, type checking, etc.

    Imo this is a good thing, laziness shouldn't be semantically important. The ability to force disable laziness while maintaining semantics is important for linting and testing, and more often than not, circular imports are a sign of bad code structure.

  • mhashemi 1 hour ago
    I've got my reservations about lazy imports, but scipy in particular is such a memory hog, I've increasingly been vendoring smaller utilities out of it. Good lazy imports would be a big help.