Add 'color' and 'size' to arguments

pandas/plotting/_core.py

@@ -1127,6 +1127,13 @@ def bar(self, x=None, y=None, **kwargs):
         axis of the plot shows the specific categories being compared, and the
         other axis represents a measured value.
         """
+        c = kwargs.pop("c", None)
+        color = kwargs.pop("color", None)
+        if c is not None and color is not None:
+            raise TypeError("Specify exactly one of `c` and `color`")
+        elif c is not None or color is not None:
+            kwargs["color"] = color if color is not None else c
+
         return self(kind="bar", x=x, y=y, **kwargs)
 
     @Appender(
@@ -1213,6 +1220,13 @@ def barh(self, x=None, y=None, **kwargs):
         axis of the plot shows the specific categories being compared, and the
         other axis represents a measured value.
         """
+        c = kwargs.pop("c", None)
+        color = kwargs.pop("color", None)
+        if c is not None and color is not None:
+            raise TypeError("Specify exactly one of `c` and `color`")
+        elif c is not None or color is not None:
+            kwargs["color"] = color if color is not None else c
+
         return self(kind="barh", x=x, y=y, **kwargs)
 
     def box(self, by=None, **kwargs):
@@ -1665,7 +1679,19 @@ def scatter(self, x, y, s=None, c=None, **kwargs):
             ...                       c='species',
             ...                       colormap='viridis')
         """
-        return self(kind="scatter", x=x, y=y, s=s, c=c, **kwargs)
+        size = kwargs.pop("size", None)
+        if s is not None and size is not None:
+            raise TypeError("Specify exactly one of `s` and `size`")
+        elif s is not None or size is not None:
+            kwargs["s"] = s if s is not None else size
+
+        color = kwargs.pop("color", None)
+        if c is not None and color is not None:
+            raise TypeError("Specify exactly one of `c` and `color`")
+        elif c is not None or color is not None:
+            kwargs["c"] = c if c is not None else color
+
+        return self(kind="scatter", x=x, y=y, **kwargs)
 
     def hexbin(self, x, y, C=None, reduce_C_function=None, gridsize=None, **kwargs):
         """

pandas/tests/plotting/frame/test_frame.py

@@ -1,4 +1,3 @@
-""" Test cases for DataFrame.plot """
 from datetime import (
     date,
     datetime,
@@ -674,6 +673,11 @@ def test_plot_scatter(self):
         with pytest.raises(TypeError, match=msg):
             df.plot.scatter(y="y")
 
+        with pytest.raises(TypeError, match="Specify exactly one of `s` and `size`"):
+            df.plot.scatter(x="x", y="y", s=2, size=2)
+        with pytest.raises(TypeError, match="Specify exactly one of `c` and `color`"):
+            df.plot.scatter(x="a", y="b", c="red", color="green")
+
         # GH 6951
         axes = df.plot(x="x", y="y", kind="scatter", subplots=True)
         self._check_axes_shape(axes, axes_num=1, layout=(1, 1))
@@ -827,6 +831,10 @@ def test_plot_bar(self):
         _check_plot_works(df.plot.bar)
 
         df = DataFrame({"a": [0, 1], "b": [1, 0]})
+
+        with pytest.raises(TypeError, match="Specify exactly one of `c` and `color`"):
+            df.plot.bar(x="a", y="b", c="red", color="green")
+
         ax = _check_plot_works(df.plot.bar)
         self._check_ticks_props(ax, xrot=90)
 

pandas/tests/plotting/frame/test_frame_color.py

@@ -123,6 +123,11 @@ def test_bar_colors(self):
         self._check_colors(ax.patches[::5], facecolors=custom_colors)
         tm.close()
 
+        custom_colors = "rgcby"
+        ax = df.plot.bar(c=custom_colors)
+        self._check_colors(ax.patches[::5], facecolors=custom_colors)
+        tm.close()
+
         from matplotlib import cm
 
         # Test str -> colormap functionality
@@ -141,6 +146,10 @@ def test_bar_colors(self):
         self._check_colors([ax.patches[0]], facecolors=["DodgerBlue"])
         tm.close()
 
+        ax = df.loc[:, [0]].plot.bar(c="DodgerBlue")
+        self._check_colors([ax.patches[0]], facecolors=["DodgerBlue"])
+        tm.close()
+
         ax = df.plot(kind="bar", color="green")
         self._check_colors(ax.patches[::5], facecolors=["green"] * 5)
         tm.close()
@@ -151,14 +160,19 @@ def test_bar_user_colors(self):
         )
         # This should *only* work when `y` is specified, else
         # we use one color per column
-        ax = df.plot.bar(y="A", color=df["color"])
-        result = [p.get_facecolor() for p in ax.patches]
         expected = [
             (1.0, 0.0, 0.0, 1.0),
             (0.0, 0.0, 1.0, 1.0),
             (0.0, 0.0, 1.0, 1.0),
             (1.0, 0.0, 0.0, 1.0),
         ]
+
+        ax = df.plot.bar(y="A", color=df["color"])
+        result = [p.get_facecolor() for p in ax.patches]
+        assert result == expected
+
+        ax = df.plot.bar(y="A", c=df["color"])
+        result = [p.get_facecolor() for p in ax.patches]
         assert result == expected
 
     def test_if_scatterplot_colorbar_affects_xaxis_visibility(self):
@@ -223,6 +237,9 @@ def test_scatter_with_c_column_name_with_colors(self, cmap):
         ax = df.plot.scatter(x=0, y=1, c="species", cmap=cmap)
         assert ax.collections[0].colorbar is None
 
+        ax = df.plot.scatter(x=0, y=1, color="species", cmap=cmap)
+        assert ax.collections[0].colorbar is None
+
     def test_scatter_colors(self):
         df = DataFrame({"a": [1, 2, 3], "b": [1, 2, 3], "c": [1, 2, 3]})
         with pytest.raises(TypeError, match="Specify exactly one of `c` and `color`"):

pandas/tests/plotting/test_series.py

@@ -268,16 +268,19 @@ def test_bar_ignore_index(self):
         ax = df.plot.bar(use_index=False, ax=ax)
         self._check_text_labels(ax.get_xticklabels(), ["0", "1", "2", "3"])
 
-    def test_bar_user_colors(self):
+    @pytest.mark.parametrize("kw", ["c", "color"])
+    def test_bar_user_colors(self, kw):
         s = Series([1, 2, 3, 4])
-        ax = s.plot.bar(color=["red", "blue", "blue", "red"])
-        result = [p.get_facecolor() for p in ax.patches]
+
         expected = [
             (1.0, 0.0, 0.0, 1.0),
             (0.0, 0.0, 1.0, 1.0),
             (0.0, 0.0, 1.0, 1.0),
             (1.0, 0.0, 0.0, 1.0),
         ]
+
+        ax = s.plot.bar(**{kw: ["red", "blue", "blue", "red"]})
+        result = [p.get_facecolor() for p in ax.patches]
         assert result == expected
 
     def test_rotation(self):