import sys import types import pkg_resources import pytest import pandas.util._test_decorators as td import pandas dummy_backend = types.ModuleType("pandas_dummy_backend") setattr(dummy_backend, "plot", lambda *args, **kwargs: "used_dummy") pytestmark = pytest.mark.slow @pytest.fixture def restore_backend(): """Restore the plotting backend to matplotlib""" pandas.set_option("plotting.backend", "matplotlib") yield pandas.set_option("plotting.backend", "matplotlib") 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): 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): 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" @td.skip_if_no_mpl def test_register_entrypoint(restore_backend): dist = pkg_resources.get_distribution("pandas") if dist.module_path not in pandas.__file__: # We are running from a non-installed pandas, and this test is invalid pytest.skip("Testing a non-installed pandas") mod = types.ModuleType("my_backend") mod.plot = lambda *args, **kwargs: 1 backends = pkg_resources.get_entry_map("pandas") my_entrypoint = pkg_resources.EntryPoint( "pandas_plotting_backend", mod.__name__, dist=dist ) backends["pandas_plotting_backends"]["my_backend"] = my_entrypoint # TODO: the docs recommend importlib.util.module_from_spec. But this works for now. sys.modules["my_backend"] = mod result = pandas.plotting._core._get_plot_backend("my_backend") assert result is mod # TODO: https://github.com/pandas-dev/pandas/issues/27517 # Remove the td.skip_if_no_mpl with pandas.option_context("plotting.backend", "my_backend"): result = pandas.plotting._core._get_plot_backend() assert result is mod def test_setting_backend_without_plot_raises(): # GH-28163 module = types.ModuleType("pandas_plot_backend") 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_mpl def test_no_matplotlib_ok(): with pytest.raises(ImportError): pandas.plotting._core._get_plot_backend("matplotlib") def test_extra_kinds_ok(monkeypatch, restore_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")