move init.py to my.core

my/core/init.py

@@ -0,0 +1,65 @@
+'''
+A hook to insert user's config directory into Python's search path.
+
+- Ideally that would be in __init__.py (so it's executed without having to import explicityly)
+  But, with namespace packages, we can't have __init__.py in the parent subpackage
+  (see http://python-notes.curiousefficiency.org/en/latest/python_concepts/import_traps.html#the-init-py-trap)
+
+  Please let me know if you are aware of a better way of dealing with this!
+'''
+
+
+# TODO not ideal to keep it here, but this should really be a leaf in the import tree
+def assign_module(parent: str, name: str, module):
+    import sys
+    import importlib
+    parent_module = importlib.import_module(parent)
+    sys.modules[parent + '.' + name] = module
+    if sys.version_info.minor == 6:
+        # ugh. not sure why it's necessary in py36...
+        # TODO that crap should be tested... I guess will get it for free when I run rest of tests in the matrix
+        setattr(parent_module, name, module)
+
+
+# separate function to present namespace pollution
+def setup_config():
+    from pathlib import Path
+    import sys
+    import os
+    import warnings
+
+    # not sure if that's necessary, i.e. could rely on PYTHONPATH instead
+    # on the other hand, by using MY_CONFIG we are guaranteed to load it from the desired path?
+    mvar = os.environ.get('MY_CONFIG')
+    if mvar is not None:
+        mycfg_dir = Path(mvar)
+    else:
+        # TODO use appdir??
+        cfg_dir = Path('~/.config').expanduser()
+        mycfg_dir = cfg_dir / 'my'
+
+    if not mycfg_dir.exists():
+        warnings.warn(f"my.config package isn't found! (expected at {mycfg_dir}). This is likely to result in issues.")
+        return
+
+    mpath = str(mycfg_dir)
+    # NOTE: we _really_ want to have mpath in front there, to shadow my.config stub within this packages
+    # hopefully it doesn't cause any issues
+    sys.path.insert(0, mpath)
+
+    # remove the stub and insert reimport hte 'real' config
+    if 'my.config' in sys.modules:
+        # TODO FIXME make sure this method isn't called twice...
+        del sys.modules['my.config']
+    try:
+        # todo import_from instead?? dunno
+        import my.config
+    except ImportError as ex:
+        # just in case... who knows what crazy setup users have in mind.
+        warnings.warn(f"Importing my.config failed! (error: {ex}). This is likely to result in issues.")
+
+
+setup_config()
+del setup_config
+
+# TODO move to my.core?