Use a more elaborate init file instead of suppressing warnings.

docs/source/conf.py

@@ -132,11 +132,6 @@
 autoapi_dirs = ['../../trx']
 autoapi_ignore = ['*test*', '*version*']
 
-# Added to suppress warnings from autoapi about import of _version
-# within __init__.py:
-suppress_warnings = ['autoapi.python_import_resolution']
-
-
 # Sphinx gallery configuration
 sphinx_gallery_conf = {
      'examples_dirs': '../../examples',

trx/__init__.py

@@ -1,3 +1,14 @@
 """TRX file format for brain tractography data."""
 
-from ._version import __version__  # noqa: F401
+try:
+    from .version import __version__  # noqa: F401
+except ImportError:
+    try:
+        from importlib.metadata import PackageNotFoundError, version
+    except ImportError:  # pragma: no cover
+        __version__ = "0+unknown"
+    else:
+        try:
+            __version__ = version("trx-python")
+        except PackageNotFoundError:
+            __version__ = "0+unknown"