fix(vega#2672): replace entrypoints with importlib.metadata

altair/utils/plugin_registry.py

@@ -1,13 +1,26 @@
 from typing import Any, Dict, List, Optional, Generic, TypeVar, cast
 from types import TracebackType
 
-import entrypoints
+try:
+    from importlib.metadata import entry_points
+except ImportError:
+    from importlib_metadata import entry_points
+
 from toolz import curry
 
 
 PluginType = TypeVar("PluginType")
 
 
+class NoSuchEntryPoint(Exception):
+    def __init__(self, group, name):
+        self.group = group
+        self.name = name
+
+    def __str__(self):
+        return f"No {self.name!r} entry point found in group {self.group!r}"
+
+
 class PluginEnabler(object):
     """Context manager for enabling plugins
 
@@ -108,9 +121,7 @@ def register(self, name: str, value: Optional[PluginType]) -> Optional[PluginTyp
     def names(self) -> List[str]:
         """List the names of the registered and entry points plugins."""
         exts = list(self._plugins.keys())
-        more_exts = [
-            ep.name for ep in entrypoints.get_group_all(self.entry_point_group)
-        ]
+        more_exts = [ep.name for ep in entry_points(group=self.entry_point_group)]
         exts.extend(more_exts)
         return sorted(set(exts))
 
@@ -139,12 +150,12 @@ def _set_state(self, state: Dict[str, Any]) -> None:
     def _enable(self, name: str, **options) -> None:
         if name not in self._plugins:
             try:
-                ep = entrypoints.get_single(self.entry_point_group, name)
-            except entrypoints.NoSuchEntryPoint:
+                (ep,) = entry_points(group=self.entry_point_group, name=name)
+            except ValueError:
                 if name in self.entrypoint_err_messages:
                     raise ValueError(self.entrypoint_err_messages[name])
                 else:
-                    raise
+                    raise NoSuchEntryPoint(self.entry_point_group, name)
             value = cast(PluginType, ep.load())
             self.register(name, value)
         self._active_name = name

doc/getting_started/installation.rst

@@ -24,7 +24,7 @@ Altair has the following dependencies, all of which are installed automatically
 with the above installation commands:
 
 - python 3.6 or newer
-- entrypoints_
+- importlib_metadata_ (python<3.8)
 - jsonschema_
 - NumPy_
 - Pandas_
@@ -74,7 +74,7 @@ development version directly from GitHub using:
 .. _Zeppelin: https://zeppelin.apache.org/
 .. _IPython: https://github.com/ipython/ipython
 
-.. _entrypoints: https://github.com/takluyver/entrypoints
+.. _importlib_metadata: https://github.com/python/importlib_metadata
 .. _jsonschema: https://github.com/Julian/jsonschema
 .. _NumPy: http://www.numpy.org/
 .. _Pandas: http://pandas.pydata.org

doc/user_guide/display_frontends.rst

@@ -40,7 +40,7 @@ Some of the built-in renderers are:
   newer versions of JupyterLab_, nteract_, and `VSCode-Python`_, but does not work
   with the `Jupyter Notebook`_, or with tools like nbviewer_ and nbconvert_.
 
-Other renderers can be installed by third-party packages via Python's entrypoints_ system;
+Other renderers can be installed by third-party packages via Python's entrypoints system;
 see :ref:`renderer-api`.
 
 
@@ -79,7 +79,7 @@ Optionally, for offline rendering in Jupyter Notebook, you can use the notebook
 
     # Optional in Jupyter Notebook: requires an up-to-date vega nbextension.
     alt.renderers.enable('notebook')
-    
+
 This renderer is provided by the `ipyvega`_ notebook extension. which can be
 installed and enabled either using pip:
 
@@ -262,10 +262,9 @@ To register and enable a new renderer::
     >>> alt.renderers.register('custom_renderer', custom_renderer)
     >>> alt.renderers.enable('custom_renderer')
 
-Renderers can also be registered using the `entrypoints`_ API of Python packages.
+Renderers can also be registered using the `entrypoints` API of Python packages.
 For an example, see `ipyvega`_.
 
-.. _entrypoints: https://github.com/takluyver/entrypoints
 .. _ipyvega: https://github.com/vega/ipyvega/
 .. _JupyterLab: http://jupyterlab.readthedocs.io/en/stable/
 .. _nteract: https://nteract.io

requirements.txt

@@ -1,4 +1,4 @@
-entrypoints
+importlib_metadata; python_version < "3.8"
 jinja2
 jsonschema>=3.0
 numpy