Lazy import

src/eyetrax/__init__.py

@@ -1,20 +1,34 @@
-from ._version import __version__
-from .gaze import GazeEstimator
-from .filters import make_kalman
+from importlib import metadata as _md
 
-from .calibration import (
-    run_9_point_calibration,
-    run_5_point_calibration,
-    run_lissajous_calibration,
-    fine_tune_kalman_filter,
-)
+__version__: str = _md.version(__name__)
 
-__all__ = [
-    "__version__",
-    "GazeEstimator",
-    "make_kalman",
-    "run_9_point_calibration",
-    "run_5_point_calibration",
-    "run_lissajous_calibration",
-    "fine_tune_kalman_filter",
-]
+_lazy_map = {
+    "GazeEstimator": ("eyetrax.gaze", "GazeEstimator"),
+    "make_kalman": ("eyetrax.filters", "make_kalman"),
+    "run_9_point_calibration": ("eyetrax.calibration", "run_9_point_calibration"),
+    "run_5_point_calibration": ("eyetrax.calibration", "run_5_point_calibration"),
+    "run_lissajous_calibration": ("eyetrax.calibration", "run_lissajous_calibration"),
+    "fine_tune_kalman_filter": ("eyetrax.calibration", "fine_tune_kalman_filter"),
+}
+
+
+def __getattr__(name: str):
+    try:
+        module_name, symbol = _lazy_map[name]
+    except KeyError:
+        raise AttributeError(name) from None
+
+    import importlib
+
+    module = importlib.import_module(module_name)
+    value = getattr(module, symbol)
+    globals()[name] = value
+    return value
+
+
+def __dir__():
+    std_attrs = set(globals()) | {"__getattr__", "__dir__"}
+    return sorted(std_attrs | _lazy_map.keys())
+
+
+__all__ = list(_lazy_map) + ["__version__"]