Added more docstrings

Author: forman

chartlets.py/chartlets/extension.py

@@ -4,16 +4,29 @@
 
 
 class Extension:
-    """A UI Extension."""
+    """An extension for a UI application that
+    uses the Chartlets JS framework."""
 
     _contrib_points: dict[type[Contribution], str] = {}
 
     @classmethod
     def add_contrib_point(cls, name: str, item_type: type[Contribution]):
+        """Add a contribution point.
+
+        Args:
+            name: The name of the contribution point.
+            item_type: The type of items that can be added
+                to the new contribution point.
+        """
         cls._contrib_points[item_type] = name
 
     @classmethod
     def get_contrib_point_names(cls) -> tuple[str, ...]:
+        """Get names of all known contribution points added
+        by the `add_contrib_point()` method.
+
+        Returns: Tuple of registered contribution point names.
+        """
         values = cls._contrib_points.values()
         # noinspection PyTypeChecker
         return tuple(values)
@@ -26,6 +39,13 @@ def __init__(self, name: str, version: str = "0.0.0"):
             setattr(self, contrib_point_name, [])
 
     def add(self, contribution: Contribution):
+        """Add a contribution to this extension.
+
+        Args:
+            contribution: The contribution.
+                Its type must be an instance of one of the
+                registered contribution types.
+        """
         contrib_type = type(contribution)
         contrib_point_name = self._contrib_points.get(contrib_type)
         if contrib_point_name is None:
@@ -37,6 +57,10 @@ def add(self, contribution: Contribution):
         contributions.append(contribution)
 
     def to_dict(self) -> dict[str, Any]:
+        """Convert this extension into a JSON-serializable dictionary.
+
+        Returns: A dictionary representing this extension.
+        """
         return dict(
             name=self.name,
             version=self.version,