feat: Warning for duplicated packages

- Added tests
- created doc .rst file

Co-authored-by: Afonso Antunes <[email protected]>

Author: PedroM4rques

doc/source/user_guide/entry_points.rst

@@ -0,0 +1 @@
+TODO

pandas/core/accessor.py

@@ -407,10 +407,23 @@ class DataFrameAccessorLoader:
     def load(cls) -> None:
         """loads and registers accessors defined by 'pandas_dataframe_accessor'."""
         eps = entry_points(group=cls.ENTRY_POINT_GROUP)
+        names: set[str] = set()
 
         for ep in eps:
             name: str = ep.name
 
+            if name in names:  # Verifies duplicated package names
+                warnings.warn(
+                    f"Warning: you have two packages with the same name: '{name}'. "
+                    "Uninstall the package you don't want to use "
+                    "in order to remove this warning.\n",
+                    UserWarning,
+                    stacklevel=2,
+                )
+
+            else:
+                names.add(name)
+
             def make_property(ep):
                 def accessor(self) -> Any:
                     cls_ = ep.load()

pandas/tests/test_plugis_entrypoint_loader.py

@@ -1,4 +1,5 @@
 import pandas as pd
+from pandas._testing._warnings import assert_produces_warning
 from pandas.core.accessor import DataFrameAccessorLoader
 
 
@@ -33,3 +34,181 @@ def mock_entry_points(*, group):
     df = pd.DataFrame({"a": [1, 2, 3]})
     assert hasattr(df, "test_accessor")
     assert df.test_accessor.test_method() == "success"
+
+
+def test_duplicate_accessor_names(monkeypatch):
+    # GH29076
+    # Create plugin
+    class MockEntryPoint1:
+        name = "duplicate_accessor"
+
+        def load(self):
+            class Accessor1:
+                def __init__(self, df):
+                    self._df = df
+
+                def which(self):
+                    return "Accessor1"
+
+            return Accessor1
+
+    # Create plugin
+    class MockEntryPoint2:
+        name = "duplicate_accessor"
+
+        def load(self):
+            class Accessor2:
+                def __init__(self, df):
+                    self._df = df
+
+                def which(self):
+                    return "Accessor2"
+
+            return Accessor2
+
+    def mock_entry_points(*, group):
+        if group == DataFrameAccessorLoader.ENTRY_POINT_GROUP:
+            return [MockEntryPoint1(), MockEntryPoint2()]
+        return []
+
+    monkeypatch.setattr("pandas.core.accessor.entry_points", mock_entry_points)
+
+    # Check that the UserWarning is raised
+    with assert_produces_warning(UserWarning, match="duplicate_accessor") as record:
+        DataFrameAccessorLoader.load()
+
+    messages = [str(w.message) for w in record]
+    assert any("two packages with the same name" in msg for msg in messages)
+
+    df = pd.DataFrame({"x": [1, 2, 3]})
+    assert hasattr(df, "duplicate_accessor")
+    assert df.duplicate_accessor.which() in {"Accessor1", "Accessor2"}
+
+
+def test_unique_accessor_names(monkeypatch):
+    # GH29076
+    # Create plugin
+    class MockEntryPoint1:
+        name = "accessor1"
+
+        def load(self):
+            class Accessor1:
+                def __init__(self, df):
+                    self._df = df
+
+                def which(self):
+                    return "Accessor1"
+
+            return Accessor1
+
+    # Create plugin
+    class MockEntryPoint2:
+        name = "accessor2"
+
+        def load(self):
+            class Accessor2:
+                def __init__(self, df):
+                    self._df = df
+
+                def which(self):
+                    return "Accessor2"
+
+            return Accessor2
+
+    def mock_entry_points(*, group):
+        if group == DataFrameAccessorLoader.ENTRY_POINT_GROUP:
+            return [MockEntryPoint1(), MockEntryPoint2()]
+        return []
+
+    monkeypatch.setattr("pandas.core.accessor.entry_points", mock_entry_points)
+
+    # Check that no UserWarning is raised
+    with assert_produces_warning(None, check_stacklevel=False):
+        DataFrameAccessorLoader.load()
+
+    df = pd.DataFrame({"x": [1, 2, 3]})
+    assert hasattr(df, "accessor1"), "Accessor1 not registered"
+    assert hasattr(df, "accessor2"), "Accessor2 not registered"
+    assert df.accessor1.which() == "Accessor1", "Accessor1 method incorrect"
+    assert df.accessor2.which() == "Accessor2", "Accessor2 method incorrect"
+
+
+def test_duplicate_and_unique_accessor_names(monkeypatch):
+    # GH29076
+    # Create plugin
+    class MockEntryPoint1:
+        name = "duplicate_accessor"
+
+        def load(self):
+            class Accessor1:
+                def __init__(self, df):
+                    self._df = df
+
+                def which(self):
+                    return "Accessor1"
+
+            return Accessor1
+
+    # Create plugin
+    class MockEntryPoint2:
+        name = "duplicate_accessor"
+
+        def load(self):
+            class Accessor2:
+                def __init__(self, df):
+                    self._df = df
+
+                def which(self):
+                    return "Accessor2"
+
+            return Accessor2
+
+    # Create plugin
+    class MockEntryPoint3:
+        name = "unique_accessor"
+
+        def load(self):
+            class Accessor3:
+                def __init__(self, df):
+                    self._df = df
+
+                def which(self):
+                    return "Accessor3"
+
+            return Accessor3
+
+    def mock_entry_points(*, group):
+        if group == DataFrameAccessorLoader.ENTRY_POINT_GROUP:
+            return [MockEntryPoint1(), MockEntryPoint2(), MockEntryPoint3()]
+        return []
+
+    monkeypatch.setattr("pandas.core.accessor.entry_points", mock_entry_points)
+
+    # Capture warnings
+    with assert_produces_warning(UserWarning, match="duplicate_accessor") as record:
+        DataFrameAccessorLoader.load()
+
+    messages = [str(w.message) for w in record]
+
+    # Filter warnings for the specific message about duplicate packages
+    duplicate_package_warnings = [
+        msg
+        for msg in messages
+        if "you have two packages with the same name: 'duplicate_accessor'" in msg
+    ]
+
+    # Assert one warning about duplicate packages
+    assert len(duplicate_package_warnings) == 1, (
+        f"Expected exactly one warning about duplicate packages, "
+        f"got {len(duplicate_package_warnings)}: {duplicate_package_warnings}"
+    )
+
+    df = pd.DataFrame({"x": [1, 2, 3]})
+    assert hasattr(df, "duplicate_accessor"), "duplicate_accessor not registered"
+
+    assert hasattr(df, "unique_accessor"), "unique_accessor not registered"
+
+    assert df.duplicate_accessor.which() in {"Accessor1", "Accessor2"}, (
+        "duplicate_accessor method incorrect"
+    )
+    assert df.unique_accessor.which() == "Accessor3", "unique_accessor method incorrect"