Updated script that can be controled by Nodejs web app

lib/python3.13/site-packages/pandas/tests/plotting/test_backend.py

@@ -0,0 +1,98 @@
+import sys
+import types
+
+import pytest
+
+import pandas.util._test_decorators as td
+
+import pandas
+
+
+@pytest.fixture
+def dummy_backend():
+    db = types.ModuleType("pandas_dummy_backend")
+    setattr(db, "plot", lambda *args, **kwargs: "used_dummy")
+    return db
+
+
+@pytest.fixture
+def restore_backend():
+    """Restore the plotting backend to matplotlib"""
+    with pandas.option_context("plotting.backend", "matplotlib"):
+        yield
+
+
+def test_backend_is_not_module():
+    msg = "Could not find plotting backend 'not_an_existing_module'."
+    with pytest.raises(ValueError, match=msg):
+        pandas.set_option("plotting.backend", "not_an_existing_module")
+
+    assert pandas.options.plotting.backend == "matplotlib"
+
+
+def test_backend_is_correct(monkeypatch, restore_backend, dummy_backend):
+    monkeypatch.setitem(sys.modules, "pandas_dummy_backend", dummy_backend)
+
+    pandas.set_option("plotting.backend", "pandas_dummy_backend")
+    assert pandas.get_option("plotting.backend") == "pandas_dummy_backend"
+    assert (
+        pandas.plotting._core._get_plot_backend("pandas_dummy_backend") is dummy_backend
+    )
+
+
+def test_backend_can_be_set_in_plot_call(monkeypatch, restore_backend, dummy_backend):
+    monkeypatch.setitem(sys.modules, "pandas_dummy_backend", dummy_backend)
+    df = pandas.DataFrame([1, 2, 3])
+
+    assert pandas.get_option("plotting.backend") == "matplotlib"
+    assert df.plot(backend="pandas_dummy_backend") == "used_dummy"
+
+
+def test_register_entrypoint(restore_backend, tmp_path, monkeypatch, dummy_backend):
+    monkeypatch.syspath_prepend(tmp_path)
+    monkeypatch.setitem(sys.modules, "pandas_dummy_backend", dummy_backend)
+
+    dist_info = tmp_path / "my_backend-0.0.0.dist-info"
+    dist_info.mkdir()
+    # entry_point name should not match module name - otherwise pandas will
+    # fall back to backend lookup by module name
+    (dist_info / "entry_points.txt").write_bytes(
+        b"[pandas_plotting_backends]\nmy_ep_backend = pandas_dummy_backend\n"
+    )
+
+    assert pandas.plotting._core._get_plot_backend("my_ep_backend") is dummy_backend
+
+    with pandas.option_context("plotting.backend", "my_ep_backend"):
+        assert pandas.plotting._core._get_plot_backend() is dummy_backend
+
+
+def test_setting_backend_without_plot_raises(monkeypatch):
+    # GH-28163
+    module = types.ModuleType("pandas_plot_backend")
+    monkeypatch.setitem(sys.modules, "pandas_plot_backend", module)
+
+    assert pandas.options.plotting.backend == "matplotlib"
+    with pytest.raises(
+        ValueError, match="Could not find plotting backend 'pandas_plot_backend'."
+    ):
+        pandas.set_option("plotting.backend", "pandas_plot_backend")
+
+    assert pandas.options.plotting.backend == "matplotlib"
+
+
+@td.skip_if_installed("matplotlib")
+def test_no_matplotlib_ok():
+    msg = (
+        'matplotlib is required for plotting when the default backend "matplotlib" is '
+        "selected."
+    )
+    with pytest.raises(ImportError, match=msg):
+        pandas.plotting._core._get_plot_backend("matplotlib")
+
+
+def test_extra_kinds_ok(monkeypatch, restore_backend, dummy_backend):
+    # https://github.com/pandas-dev/pandas/pull/28647
+    monkeypatch.setitem(sys.modules, "pandas_dummy_backend", dummy_backend)
+    pandas.set_option("plotting.backend", "pandas_dummy_backend")
+    df = pandas.DataFrame({"A": [1, 2, 3]})
+    df.plot(kind="not a real kind")