feat: Lazily load project submodules

pyproject.toml

@@ -93,6 +93,7 @@ dependencies = [
     "hapiclient>=0.2.2",
     "pytplot-mpl-temp>=2.2.49",
     "viresclient",
+    "lazy-loader"
 ]
 
 [project.urls]

pyspedas/__init__.py

@@ -85,70 +85,29 @@
 # The code below is needed for backward compatibility, so users can continue to do things
 # like "from pyspedas.mms import mec" even after mms has been moved to the projects directory.
 
-import sys
 from importlib import import_module
 
 # List of submodules we want to make available under the pyspedas namespace
 submodules = ['ace', 'akebono', 'barrel', 'cluster', 'cnofs', 'csswe', 'de2', 'dscovr',
              'elfin', 'equator_s', 'erg', 'fast', 'geotail', 'goes', 'image', 'kompsat',
               'kyoto', 'lanl', 'maven', 'mica', 'mms', 'noaa', 'omni', 'poes', 'polar', 'psp',
               'rbsp', 'secs', 'soho', 'solo', 'st5', 'stereo', 'swarm', 'themis', 'themis.state', 'twins',
-              'ulysses'
+              'ulysses', "wind"
               ]
-
-for submodule in submodules:
-    # Import the module from the new path
-    full_module_path = f"pyspedas.projects.{submodule}"
-    imported_module = import_module(full_module_path)
-
-    # Add it to sys.modules under the old path
-    sys.modules[f"pyspedas.{submodule}"] = imported_module
+
+def __getattr__(name):
+    if name in submodules:
+        return import_module(".projects." + name, __name__)
+    raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
 
 # This set of imports is still needed for backward compatibility, when using fully-qualified
 # routine names in function calls, like "pyspedas.mms.mec()" rather than "pyspedas.projects.mms.mec()"
 
 # Make mission-specific namespaces available under pyspedas
-from .projects import ace
-from .projects import akebono
-from .projects import barrel
-from .projects import cluster
-from .projects import cnofs
-from .projects import csswe
-from .projects import de2
-from .projects import dscovr
-from .projects import elfin
-from .projects import equator_s
-from .projects import erg
-from .projects import fast
-from .projects import geotail
-from .projects import goes
-from .projects import image
-from .projects import kompsat
 # for backward compatibility
 from .projects.kompsat.load import load as kompsat_load
-from .projects import kyoto
-from .projects import lanl
-from .projects import maven
-# for backward compatibility
 from .projects.maven import maven_load
-from .projects import mica
-from .projects import mms
-from .projects import noaa
-from .projects import poes
-from .projects import polar
-from .projects import psp
-from .projects import rbsp
-from .projects import secs
-from .projects import soho
-from .projects import solo
-from .projects import st5
-from .projects import stereo
-from .projects import swarm
-from .projects import themis
-from .projects import twins
-from .projects import ulysses
 from . import vires
-from .projects import wind
 
 # set up logging/console output
 import logging

pyspedas/projects/__init__.py

@@ -0,0 +1,43 @@
+import lazy_loader as lazy
+
+submodules = [
+    "ace",
+    "akebono",
+    "barrel",
+    "cluster",
+    "cnofs",
+    "csswe",
+    "de2",
+    "dscovr",
+    "elfin",
+    "equator_s",
+    "erg",
+    "fast",
+    "geotail",
+    "goes",
+    "image",
+    "kompsat",
+    "kyoto",
+    "lanl",
+    "maven",
+    "mica",
+    "mms",
+    "noaa",
+    "omni",
+    "poes",
+    "polar",
+    "psp",
+    "rbsp",
+    "secs",
+    "soho",
+    "solo",
+    "st5",
+    "stereo",
+    "swarm",
+    "themis",
+    "themis.state",
+    "twins",
+    "ulysses",
+]
+
+__getattr__, __dir__, _ = lazy.attach(__name__, submodules)