Problems accessing scipp.constants

[arm61]

The following raises an error for me:

import scipp as sc
sc.constants

But works if I do

from scipp import constants

Scipp version: 24.9.1

[SimonHeybrock]

Hi! This is by design. Similar to, say SciPy submodules, it is a submodule that needs to be imported explicitly. One reason for this is that it relies on Scipy, which is an optional dependency of Scipp.

If you would like to use sc.constants in code, you can

import scipp as sc
import scipp.constants

sc.constants.h  # works now

[SimonHeybrock]

Hmm, at least some of Scipy's submodules used to do that.

[arm61]

Perhaps the physical_constants subsubmodule?

[SimonHeybrock]

Seemed to be all: https://github.com/scipy/scipy/blob/4d7413563cfa477c08717daa61e5994e968ee79f/scipy/__init__.py#LL15C1-L16C26

[jl-wynen]

Scipy imports modules lazily when you access them: https://github.com/scipy/scipy/blob/1adc8cb7a37e09444632a86afea5ee1d07f3e3c5/scipy/__init__.py#L134
We could do the same but I am not sure it is worth the complication.

[SimonHeybrock]

There is actually a SPEC about it: https://scientific-python.org/specs/spec-0001/