PLT: Cleaner plotting backend API, and unify Series and DataFrame accessors

pandas/core/frame.py

@@ -8051,7 +8051,7 @@ def isin(self, values):
 
     # ----------------------------------------------------------------------
     # Add plotting methods to DataFrame
-    plot = CachedAccessor("plot", pandas.plotting.FramePlotMethods)
+    plot = CachedAccessor("plot", pandas.plotting.PlotAccessor)
     hist = pandas.plotting.hist_frame
     boxplot = pandas.plotting.boxplot_frame
     sparse = CachedAccessor("sparse", SparseFrameAccessor)

pandas/core/series.py

@@ -4530,7 +4530,7 @@ def to_period(self, freq=None, copy=True):
     str = CachedAccessor("str", StringMethods)
     dt = CachedAccessor("dt", CombinedDatetimelikeProperties)
     cat = CachedAccessor("cat", CategoricalAccessor)
-    plot = CachedAccessor("plot", pandas.plotting.SeriesPlotMethods)
+    plot = CachedAccessor("plot", pandas.plotting.PlotAccessor)
     sparse = CachedAccessor("sparse", SparseAccessor)
 
     # ----------------------------------------------------------------------

pandas/plotting/__init__.py

@@ -2,16 +2,16 @@
 Plotting public API
 """
 from pandas.plotting._core import (
-    FramePlotMethods, SeriesPlotMethods, boxplot, boxplot_frame,
-    boxplot_frame_groupby, hist_frame, hist_series)
+    PlotAccessor, boxplot, boxplot_frame, boxplot_frame_groupby, hist_frame,
+    hist_series)
 from pandas.plotting._misc import (
     andrews_curves, autocorrelation_plot, bootstrap_plot,
     deregister as deregister_matplotlib_converters, lag_plot,
     parallel_coordinates, plot_params, radviz,
     register as register_matplotlib_converters, scatter_matrix, table)
 
 __all__ = ['boxplot', 'boxplot_frame', 'boxplot_frame_groupby', 'hist_frame',
-           'hist_series', 'FramePlotMethods', 'SeriesPlotMethods',
+           'hist_series', 'PlotAccessor',
            'scatter_matrix', 'radviz', 'andrews_curves', 'bootstrap_plot',
            'parallel_coordinates', 'lag_plot', 'autocorrelation_plot',
            'table', 'plot_params', 'register_matplotlib_converters',

pandas/plotting/_matplotlib/__init__.py

@@ -1,5 +1,9 @@
+import matplotlib.pyplot as plt
+
 from pandas._config import get_option
 
+import pandas
+
 from pandas.plotting._matplotlib.boxplot import (
     BoxPlot, boxplot, boxplot_frame, boxplot_frame_groupby)
 from pandas.plotting._matplotlib.converter import deregister, register
@@ -13,13 +17,36 @@
 from pandas.plotting._matplotlib.timeseries import tsplot
 from pandas.plotting._matplotlib.tools import table
 
+PLOT_CLASSES = {'line': LinePlot,
+                'bar': BarPlot,
+                'barh': BarhPlot,
+                'box': BoxPlot,
+                'hist': HistPlot,
+                'kde': KdePlot,
+                'area': AreaPlot,
+                'pie': PiePlot,
+                'scatter': ScatterPlot,
+                'hexbin': HexBinPlot}
+
 if get_option("plotting.matplotlib.register_converters"):
     register(explicit=False)
 
 
-__all__ = ['LinePlot', 'BarPlot', 'BarhPlot', 'HistPlot', 'BoxPlot', 'KdePlot',
-           'AreaPlot', 'PiePlot', 'ScatterPlot', 'HexBinPlot', 'hist_series',
-           'hist_frame', 'boxplot', 'boxplot_frame', 'boxplot_frame_groupby',
-           'tsplot', 'table', 'andrews_curves', 'autocorrelation_plot',
-           'bootstrap_plot', 'lag_plot', 'parallel_coordinates', 'radviz',
-           'scatter_matrix', 'register', 'deregister']
+def plot(data, kind, **kwargs):
+    if isinstance(data, pandas.core.dtypes.generic.ABCSeries):
+        ax = kwargs.get('ax')
+        if ax is None and len(plt.get_fignums()) > 0:
+            with plt.rc_context():
+                ax = plt.gca()
+            kwargs['ax'] = getattr(ax, 'left_ax', ax)
+    plot_obj = PLOT_CLASSES[kind](data, **kwargs)
+    plot_obj.generate()
+    plot_obj.draw()
+    return plot_obj.result
+
+
+__all__ = ['plot', 'hist_series', 'hist_frame', 'boxplot', 'boxplot_frame',
+           'boxplot_frame_groupby', 'tsplot', 'table', 'andrews_curves',
+           'autocorrelation_plot', 'bootstrap_plot', 'lag_plot',
+           'parallel_coordinates', 'radviz', 'scatter_matrix', 'register',
+           'deregister']

pandas/plotting/_matplotlib/timeseries.py

@@ -143,12 +143,8 @@ def _replot_ax(ax, freq, kwargs):
 
             # for tsplot
             if isinstance(plotf, str):
-                # XXX _plot_classes is private and shouldn't be imported
-                # here. But as tsplot is deprecated, and we'll remove this
-                # code soon, it's probably better to not overcomplicate
-                # things, and just leave this the way it was implemented
-                from pandas.plotting._core import _plot_classes
-                plotf = _plot_classes()[plotf]._plot
+                from pandas.plotting._matplotlib import PLOT_CLASSES
+                plotf = PLOT_CLASSES[plotf]._plot
 
             lines.append(plotf(ax, series.index._mpl_repr(),
                                series.values, **kwds)[0])

pandas/tests/plotting/test_frame.py

@@ -2225,7 +2225,7 @@ def test_unordered_ts(self):
     @td.skip_if_no_scipy
     def test_kind_both_ways(self):
         df = DataFrame({'x': [1, 2, 3]})
-        for kind in plotting._core._common_kinds:
+        for kind in plotting.PlotAccessor._common_kinds:
 
             df.plot(kind=kind)
             getattr(df.plot, kind)()
@@ -2235,7 +2235,7 @@ def test_kind_both_ways(self):
 
     def test_all_invalid_plot_data(self):
         df = DataFrame(list('abcd'))
-        for kind in plotting._core._common_kinds:
+        for kind in plotting.PlotAccessor._common_kinds:
 
             msg = "no numeric data to plot"
             with pytest.raises(TypeError, match=msg):
@@ -2246,7 +2246,7 @@ def test_partially_invalid_plot_data(self):
         with tm.RNGContext(42):
             df = DataFrame(randn(10, 2), dtype=object)
             df[np.random.rand(df.shape[0]) > 0.5] = 'a'
-            for kind in plotting._core._common_kinds:
+            for kind in plotting.PlotAccessor._common_kinds:
 
                 msg = "no numeric data to plot"
                 with pytest.raises(TypeError, match=msg):
@@ -2738,7 +2738,7 @@ def test_memory_leak(self):
         import gc
 
         results = {}
-        for kind in plotting._core._plot_classes().keys():
+        for kind in plotting.PlotAccessor._all_kinds:
 
             args = {}
             if kind in ['hexbin', 'scatter', 'pie']:
@@ -2936,7 +2936,7 @@ def test_df_grid_settings(self):
         # Make sure plot defaults to rcParams['axes.grid'] setting, GH 9792
         self._check_grid_settings(
             DataFrame({'a': [1, 2, 3], 'b': [2, 3, 4]}),
-            plotting._core._dataframe_kinds, kws={'x': 'a', 'y': 'b'})
+            plotting.PlotAccessor._dataframe_kinds, kws={'x': 'a', 'y': 'b'})
 
     def test_invalid_colormap(self):
         df = DataFrame(randn(3, 2), columns=['A', 'B'])

pandas/tests/plotting/test_series.py

@@ -684,8 +684,8 @@ def test_boxplot_series(self):
     @pytest.mark.slow
     def test_kind_both_ways(self):
         s = Series(range(3))
-        kinds = (plotting._core._common_kinds +
-                 plotting._core._series_kinds)
+        kinds = (plotting.PlotAccessor._common_kinds +
+                 plotting.PlotAccessor._series_kinds)
         _, ax = self.plt.subplots()
         for kind in kinds:
 
@@ -696,7 +696,7 @@ def test_kind_both_ways(self):
     def test_invalid_plot_data(self):
         s = Series(list('abcd'))
         _, ax = self.plt.subplots()
-        for kind in plotting._core._common_kinds:
+        for kind in plotting.PlotAccessor._common_kinds:
 
             msg = "no numeric data to plot"
             with pytest.raises(TypeError, match=msg):
@@ -705,13 +705,13 @@ def test_invalid_plot_data(self):
     @pytest.mark.slow
     def test_valid_object_plot(self):
         s = Series(range(10), dtype=object)
-        for kind in plotting._core._common_kinds:
+        for kind in plotting.PlotAccessor._common_kinds:
             _check_plot_works(s.plot, kind=kind)
 
     def test_partially_invalid_plot_data(self):
         s = Series(['a', 'b', 1.0, 2])
         _, ax = self.plt.subplots()
-        for kind in plotting._core._common_kinds:
+        for kind in plotting.PlotAccessor._common_kinds:
 
             msg = "no numeric data to plot"
             with pytest.raises(TypeError, match=msg):
@@ -781,8 +781,8 @@ def test_table(self):
     def test_series_grid_settings(self):
         # Make sure plot defaults to rcParams['axes.grid'] setting, GH 9792
         self._check_grid_settings(Series([1, 2, 3]),
-                                  plotting._core._series_kinds +
-                                  plotting._core._common_kinds)
+                                  plotting.PlotAccessor._series_kinds +
+                                  plotting.PlotAccessor._common_kinds)
 
     @pytest.mark.slow
     def test_standard_colors(self):