using inspect

[Ethan Furman]

Greetings!

How wise is it to base code on inspect? Specifically on things like
live frames on the stack and whatnot. It occurs to me that this is
leaning towards implementation details, and away from pure, pristine Python.

As an example, I have this routine in a module I'm working on:

def _get_module():
"get the calling module -- should be the config'ed module"
target = os.path.splitext(inspect.stack()[2][1])[0]
target = __import__(target)
return target

How brittle is this technique?

~Ethan~

 

[Steven D'Aprano]

Greetings!

How wise is it to base code on inspect? Specifically on things like
live frames on the stack and whatnot. It occurs to me that this is
leaning towards implementation details, and away from pure, pristine
Python.

As an example, I have this routine in a module I'm working on:

def _get_module():
"get the calling module -- should be the config'ed module" target =
os.path.splitext(inspect.stack()[2][1])[0]
target = __import__(target)
return target

How brittle is this technique?

Download and install PyPy, CLPython, IronPython and Jython and see how
many it breaks on


I think it's a brittle technique because it is creating a dependency
where there shouldn't be one. What happens if somebody runs your module
directly? It might not need to do anything sensible, but it shouldn't
fail merely because there's no calling module.

But I don't think it's inherently dangerous. It's a bit hacky, well,
probably a lot hacky, but it doesn't seem to use anything specifically
documented as implementation specific:

http://docs.python.org/library/inspect.html#inspect.stack