Use attributes Axes.x/yaxis instead of Axes.get_x/yaxis()

timhoffm · timhoffm · commit a4ab663a4054 · 2020-10-11T00:03:13.000+02:00
We're already largely doing this in code base and examples.

This PR changes some remaining usages and discourages the use of the
getters in their docstrings.

*Note on API consistency*: While we generally use getters, I'm not too
worried that people may find this inconsistent. An axis is rather a
sub-part than a property. In particular, it will mostly be used as an
indirection to one of its properties, i.e. `ax.xaxis.get_units()`.
Here we still have a final getter call. IMHO it even looks better / more
pythonic than a method chain: `ax.get_xaxis().get_units()`.

I'm also not too worried that people may try to overwrite the plain
attributes `Axes.x/yaxis`. While one could turn them into properties
to protect overwriting, the attributes have already been used widely
in examples and we did not get any complaints.
diff --git a/examples/lines_bars_and_markers/timeline.py b/examples/lines_bars_and_markers/timeline.py
@@ -83,12 +83,12 @@
                 verticalalignment="bottom" if l > 0 else "top")
 
 # format xaxis with 4 month intervals
-ax.get_xaxis().set_major_locator(mdates.MonthLocator(interval=4))
-ax.get_xaxis().set_major_formatter(mdates.DateFormatter("%b %Y"))
+ax.xaxis.set_major_locator(mdates.MonthLocator(interval=4))
+ax.xaxis.set_major_formatter(mdates.DateFormatter("%b %Y"))
 plt.setp(ax.get_xticklabels(), rotation=30, ha="right")
 
 # remove y axis and spines
-ax.get_yaxis().set_visible(False)
+ax.yaxis.set_visible(False)
 for spine in ["left", "top", "right"]:
     ax.spines[spine].set_visible(False)
 
diff --git a/examples/showcase/bachelors_degrees_by_gender.py b/examples/showcase/bachelors_degrees_by_gender.py
@@ -39,8 +39,8 @@
 
 # Ensure that the axis ticks only show up on the bottom and left of the plot.
 # Ticks on the right and top of the plot are generally unnecessary.
-ax.get_xaxis().tick_bottom()
-ax.get_yaxis().tick_left()
+ax.xaxis.tick_bottom()
+ax.yaxis.tick_left()
 
 fig.subplots_adjust(left=.06, right=.75, bottom=.02, top=.94)
 # Limit the range of the plot to only where the data is.
diff --git a/examples/statistics/customized_violin.py b/examples/statistics/customized_violin.py
@@ -28,7 +28,7 @@ def adjacent_values(vals, q1, q3):
 
 
 def set_axis_style(ax, labels):
-    ax.get_xaxis().set_tick_params(direction='out')
+    ax.xaxis.set_tick_params(direction='out')
     ax.xaxis.set_ticks_position('bottom')
     ax.set_xticks(np.arange(1, len(labels) + 1))
     ax.set_xticklabels(labels)
diff --git a/lib/matplotlib/axes/_base.py b/lib/matplotlib/axes/_base.py
@@ -1885,11 +1885,21 @@ def get_lines(self):
         return cbook.silent_list('Line2D', self.lines)
 
     def get_xaxis(self):
-        """Return the XAxis instance."""
+        """
+        Return the XAxis instance.
+
+        The use of this function is discouraged. You should instead directly
+        access the attribute ``ax.xaxis``.
+        """
         return self.xaxis
 
     def get_yaxis(self):
-        """Return the YAxis instance."""
+        """
+        Return the YAxis instance.
+
+        The use of this function is discouraged. You should instead directly
+        access the attribute ``ax.yaxis``.
+        """
         return self.yaxis
 
     get_xgridlines = _axis_method_wrapper("xaxis", "get_gridlines")
diff --git a/lib/matplotlib/axes/_subplots.py b/lib/matplotlib/axes/_subplots.py
@@ -137,12 +137,12 @@ def label_outer(self):
         if not lastrow:
             for label in self.get_xticklabels(which="both"):
                 label.set_visible(False)
-            self.get_xaxis().get_offset_text().set_visible(False)
+            self.xaxis.get_offset_text().set_visible(False)
             self.set_xlabel("")
         if not firstcol:
             for label in self.get_yticklabels(which="both"):
                 label.set_visible(False)
-            self.get_yaxis().get_offset_text().set_visible(False)
+            self.yaxis.get_offset_text().set_visible(False)
             self.set_ylabel("")
 
     def _make_twin_axes(self, *args, **kwargs):
diff --git a/lib/matplotlib/testing/jpl_units/StrConverter.py b/lib/matplotlib/testing/jpl_units/StrConverter.py
@@ -35,7 +35,7 @@ def convert(value, unit, axis):
 
         # we delay loading to make matplotlib happy
         ax = axis.axes
-        if axis is ax.get_xaxis():
+        if axis is ax.xaxis:
             isXAxis = True
         else:
             isXAxis = False
diff --git a/lib/matplotlib/tests/test_bbox_tight.py b/lib/matplotlib/tests/test_bbox_tight.py
@@ -120,8 +120,8 @@ def test_noop_tight_bbox():
     ax = plt.Axes(fig, [0., 0., 1., 1.])
     fig.add_axes(ax)
     ax.set_axis_off()
-    ax.get_xaxis().set_visible(False)
-    ax.get_yaxis().set_visible(False)
+    ax.xaxis.set_visible(False)
+    ax.yaxis.set_visible(False)
 
     data = np.arange(x_size * y_size).reshape(y_size, x_size)
     ax.imshow(data, rasterized=True)
diff --git a/lib/matplotlib/tests/test_polar.py b/lib/matplotlib/tests/test_polar.py
@@ -135,7 +135,7 @@ def test_polar_units_2(fig_test, fig_ref):
     plt.figure(fig_test.number)
     # test {theta,r}units.
     plt.polar(xs_deg, ys_km, thetaunits="rad", runits="km")
-    assert isinstance(plt.gca().get_xaxis().get_major_formatter(),
+    assert isinstance(plt.gca().xaxis.get_major_formatter(),
                       units.UnitDblFormatter)
 
     ax = fig_ref.add_subplot(projection="polar")
diff --git a/lib/matplotlib/tests/test_subplots.py b/lib/matplotlib/tests/test_subplots.py
@@ -27,10 +27,10 @@ def check_shared(axs, x_shared, y_shared):
 
 def check_visible(axs, x_visible, y_visible):
     for i, (ax, vx, vy) in enumerate(zip(axs, x_visible, y_visible)):
-        for l in ax.get_xticklabels() + [ax.get_xaxis().offsetText]:
+        for l in ax.get_xticklabels() + [ax.xaxis.offsetText]:
             assert l.get_visible() == vx, \
                     f"Visibility of x axis #{i} is incorrectly {vx}"
-        for l in ax.get_yticklabels() + [ax.get_yaxis().offsetText]:
+        for l in ax.get_yticklabels() + [ax.yaxis.offsetText]:
             assert l.get_visible() == vy, \
                     f"Visibility of y axis #{i} is incorrectly {vy}"
 
diff --git a/lib/matplotlib/tests/test_ticker.py b/lib/matplotlib/tests/test_ticker.py
@@ -527,18 +527,18 @@ def test_unicode_minus(self, unicode_minus, result):
     @pytest.mark.parametrize('left, right, offset', offset_data)
     def test_offset_value(self, left, right, offset):
         fig, ax = plt.subplots()
-        formatter = ax.get_xaxis().get_major_formatter()
+        formatter = ax.xaxis.get_major_formatter()
 
         with (pytest.warns(UserWarning, match='Attempting to set identical')
               if left == right else nullcontext()):
             ax.set_xlim(left, right)
-        ax.get_xaxis()._update_ticks()
+        ax.xaxis._update_ticks()
         assert formatter.offset == offset
 
         with (pytest.warns(UserWarning, match='Attempting to set identical')
               if left == right else nullcontext()):
             ax.set_xlim(right, left)
-        ax.get_xaxis()._update_ticks()
+        ax.xaxis._update_ticks()
         assert formatter.offset == offset
 
     @pytest.mark.parametrize('use_offset', use_offset_data)
diff --git a/lib/mpl_toolkits/tests/test_axes_grid1.py b/lib/mpl_toolkits/tests/test_axes_grid1.py
@@ -259,8 +259,8 @@ def test_fill_facecolor():
     axins = zoomed_inset_axes(ax[0], 1, loc='upper right')
     axins.set_xlim(0, 0.2)
     axins.set_ylim(0, 0.2)
-    plt.gca().axes.get_xaxis().set_ticks([])
-    plt.gca().axes.get_yaxis().set_ticks([])
+    plt.gca().axes.xaxis.set_ticks([])
+    plt.gca().axes.yaxis.set_ticks([])
     mark_inset(ax[0], axins, loc1=2, loc2=4, fc="b", ec="0.5")
 
     # fill with yellow by setting 'facecolor' field
@@ -276,8 +276,8 @@ def test_fill_facecolor():
     axins = zoomed_inset_axes(ax[1], 1, loc='upper right')
     axins.set_xlim(0, 0.2)
     axins.set_ylim(0, 0.2)
-    plt.gca().axes.get_xaxis().set_ticks([])
-    plt.gca().axes.get_yaxis().set_ticks([])
+    plt.gca().axes.xaxis.set_ticks([])
+    plt.gca().axes.yaxis.set_ticks([])
     mark_inset(ax[1], axins, loc1=2, loc2=4, facecolor="y", ec="0.5")
 
     # fill with green by setting 'color' field
@@ -293,8 +293,8 @@ def test_fill_facecolor():
     axins = zoomed_inset_axes(ax[2], 1, loc='upper right')
     axins.set_xlim(0, 0.2)
     axins.set_ylim(0, 0.2)
-    plt.gca().axes.get_xaxis().set_ticks([])
-    plt.gca().axes.get_yaxis().set_ticks([])
+    plt.gca().axes.xaxis.set_ticks([])
+    plt.gca().axes.yaxis.set_ticks([])
     mark_inset(ax[2], axins, loc1=2, loc2=4, color="g", ec="0.5")
 
     # fill with green but color won't show if set fill to False
@@ -310,8 +310,8 @@ def test_fill_facecolor():
     axins = zoomed_inset_axes(ax[3], 1, loc='upper right')
     axins.set_xlim(0, 0.2)
     axins.set_ylim(0, 0.2)
-    axins.get_xaxis().set_ticks([])
-    axins.get_yaxis().set_ticks([])
+    axins.xaxis.set_ticks([])
+    axins.yaxis.set_ticks([])
     mark_inset(ax[3], axins, loc1=2, loc2=4, fc="g", ec="0.5", fill=False)
 
 
