Prefer add_subplot(foo=bar) to subplots(subplot_kw={"foo": bar}).

anntzer · anntzer · commit fa8ef97ed9ba · 2019-06-02T00:49:17.000+02:00
When creating a single subplot I think the former is more readable.

(Note that before mpl3.1 one had to write `add_subplot(111, foo=bar)`
where the tradeoff was less clear.)
diff --git a/examples/frontpage/3D.py b/examples/frontpage/3D.py
@@ -23,7 +23,8 @@
 region = np.s_[5:50, 5:50]
 x, y, z = x[region], y[region], z[region]
 
-fig, ax = plt.subplots(subplot_kw=dict(projection='3d'))
+fig = plt.figure()
+ax = fig.add_subplot(projection='3d')
 
 ls = LightSource(270, 45)
 # To use a custom hillshading mode, override the built-in shading and pass
diff --git a/examples/mplot3d/custom_shaded_3d_surface.py b/examples/mplot3d/custom_shaded_3d_surface.py
@@ -25,7 +25,7 @@
 x, y, z = x[region], y[region], z[region]
 
 # Set up plot
-fig, ax = plt.subplots(subplot_kw=dict(projection='3d'))
+ax = plt.figure().add_subplot(projection='3d')
 
 ls = LightSource(270, 45)
 # To use a custom hillshading mode, override the built-in shading and pass
diff --git a/examples/mplot3d/wire3d_zero_stride.py b/examples/mplot3d/wire3d_zero_stride.py
@@ -11,7 +11,8 @@
 import matplotlib.pyplot as plt
 
 
-fig, [ax1, ax2] = plt.subplots(2, 1, figsize=(8, 12), subplot_kw={'projection': '3d'})
+fig, (ax1, ax2) = plt.subplots(
+    2, 1, figsize=(8, 12), subplot_kw={'projection': '3d'})
 
 # Get the test data
 X, Y, Z = axes3d.get_test_data(0.05)
diff --git a/examples/pie_and_polar_charts/nested_pie.py b/examples/pie_and_polar_charts/nested_pie.py
@@ -52,7 +52,7 @@
 # a circle. The cumulative sum of the values are used as the edges
 # of the bars.
 
-fig, ax = plt.subplots(subplot_kw=dict(polar=True))
+ax = plt.figure().add_subplot(polar=True)
 
 size = 0.3
 vals = np.array([[60., 32.], [37., 40.], [29., 10.]])
diff --git a/examples/pie_and_polar_charts/pie_and_donut_labels.py b/examples/pie_and_polar_charts/pie_and_donut_labels.py
@@ -33,7 +33,7 @@
 import numpy as np
 import matplotlib.pyplot as plt
 
-fig, ax = plt.subplots(figsize=(6, 3), subplot_kw=dict(aspect="equal"))
+ax = plt.figure(figsize=(6, 3)).add_subplot(aspect="equal")
 
 recipe = ["375 g flour",
           "75 g sugar",
@@ -88,7 +88,7 @@ def func(pct, allvals):
 #   determined parameters.
 
 
-fig, ax = plt.subplots(figsize=(6, 3), subplot_kw=dict(aspect="equal"))
+ax = plt.figure(figsize=(6, 3)).add_subplot(aspect="equal")
 
 recipe = ["225 g flour",
           "90 g sugar",
diff --git a/examples/shapes_and_collections/ellipse_demo.py b/examples/shapes_and_collections/ellipse_demo.py
@@ -18,7 +18,7 @@
                 angle=np.random.rand() * 360)
         for i in range(NUM)]
 
-fig, ax = plt.subplots(subplot_kw={'aspect': 'equal'})
+ax = plt.figure().add_subplot(aspect='equal')
 for e in ells:
     ax.add_artist(e)
     e.set_clip_box(ax.bbox)
diff --git a/examples/text_labels_and_annotations/annotation_demo.py b/examples/text_labels_and_annotations/annotation_demo.py
@@ -109,7 +109,7 @@
 # The text in the example is placed in the fractional figure coordinate system.
 # Text keyword args like horizontal and vertical alignment are respected.
 
-fig, ax = plt.subplots(subplot_kw=dict(projection='polar'), figsize=(3, 3))
+ax = plt.figure(figsize=(3, 3)).add_subplot(projection='polar')
 r = np.arange(0, 1, 0.001)
 theta = 2*2*np.pi*r
 line, = ax.plot(theta, r)
@@ -131,7 +131,7 @@
 
 el = Ellipse((0, 0), 10, 20, facecolor='r', alpha=0.5)
 
-fig, ax = plt.subplots(subplot_kw=dict(aspect='equal'))
+ax = plt.figure().add_subplot(aspect='equal')
 ax.add_artist(el)
 el.set_clip_box(ax.bbox)
 ax.annotate('the top',
diff --git a/examples/widgets/lasso_selector_demo_sgskip.py b/examples/widgets/lasso_selector_demo_sgskip.py
@@ -82,8 +82,8 @@ def disconnect(self):
 
     data = np.random.rand(100, 2)
 
-    subplot_kw = dict(xlim=(0, 1), ylim=(0, 1), autoscale_on=False)
-    fig, ax = plt.subplots(subplot_kw=subplot_kw)
+    fig = plt.figure()
+    ax = fig.add_subplot(xlim=(0, 1), ylim=(0, 1), autoscale_on=False)
 
     pts = ax.scatter(data[:, 0], data[:, 1], s=80)
     selector = SelectFromCollection(ax, pts)
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -769,21 +769,21 @@ def test_polar_theta_limits():
 
 @check_figures_equal(extensions=["png"])
 def test_polar_rlim(fig_test, fig_ref):
-    ax = fig_test.subplots(subplot_kw={'polar': True})
+    ax = fig_test.add_subplot(polar=True)
     ax.set_rlim(top=10)
     ax.set_rlim(bottom=.5)
 
-    ax = fig_ref.subplots(subplot_kw={'polar': True})
+    ax = fig_ref.add_subplot(polar=True)
     ax.set_rmax(10.)
     ax.set_rmin(.5)
 
 
 @check_figures_equal(extensions=["png"])
 def test_polar_rlim_bottom(fig_test, fig_ref):
-    ax = fig_test.subplots(subplot_kw={'polar': True})
+    ax = fig_test.add_subplot(polar=True)
     ax.set_rlim(bottom=[.5, 10])
 
-    ax = fig_ref.subplots(subplot_kw={'polar': True})
+    ax = fig_ref.add_subplot(polar=True)
     ax.set_rmax(10.)
     ax.set_rmin(.5)
 
@@ -6275,7 +6275,8 @@ def test_minor_accountedfor():
 
 
 def test_get_tightbbox_polar():
-    fig, ax = plt.subplots(subplot_kw={'projection': 'polar'})
+    fig = plt.figure()
+    ax = fig.add_subplot(projection='polar')
     fig.canvas.draw()
     bb = ax.get_tightbbox(fig.canvas.get_renderer())
     assert_allclose(bb.extents,
diff --git a/lib/matplotlib/tests/test_quiver.py b/lib/matplotlib/tests/test_quiver.py
@@ -199,7 +199,7 @@ def test_angles_and_scale():
 @image_comparison(['quiver_xy.png'], remove_text=True)
 def test_quiver_xy():
     # simple arrow pointing from SW to NE
-    fig, ax = plt.subplots(subplot_kw=dict(aspect='equal'))
+    ax = plt.figure().add_subplot(aspect='equal')
     ax.quiver(0, 0, 1, 1, angles='xy', scale_units='xy', scale=1)
     ax.set_xlim(0, 1.1)
     ax.set_ylim(0, 1.1)
diff --git a/lib/mpl_toolkits/tests/test_mplot3d.py b/lib/mpl_toolkits/tests/test_mplot3d.py
@@ -40,10 +40,7 @@ def test_bar3d_shaded():
 
     views = [(-60, 30), (30, 30), (30, -30), (120, -30)]
     fig = plt.figure(figsize=plt.figaspect(1 / len(views)))
-    axs = fig.subplots(
-        1, len(views),
-        subplot_kw=dict(projection='3d')
-    )
+    axs = fig.subplots(1, len(views), subplot_kw=dict(projection='3d'))
     for ax, (azim, elev) in zip(axs, views):
         ax.bar3d(x2d, y2d, x2d * 0, 1, 1, z, shade=True)
         ax.view_init(azim=azim, elev=elev)
@@ -612,7 +609,7 @@ def test_world():
 @image_comparison(['proj3d_lines_dists.png'],
                   remove_text=True, style='default')
 def test_lines_dists():
-    fig, ax = plt.subplots(figsize=(4, 6), subplot_kw=dict(aspect='equal'))
+    ax = plt.figure(figsize=(4, 6)).add_subplot(aspect='equal')
 
     xs = (0, 30)
     ys = (20, 150)
@@ -634,7 +631,7 @@ def test_lines_dists():
 
 
 def test_autoscale():
-    fig, ax = plt.subplots(subplot_kw={"projection": "3d"})
+    ax = plt.figure().add_subplot(projection="3d")
     ax.margins(x=0, y=.1, z=.2)
     ax.plot([0, 1], [0, 1], [0, 1])
     assert ax.get_w_lims() == (0, 1, -.1, 1.1, -.2, 1.2)
@@ -671,7 +668,7 @@ def test_invalid_axes_limits(setter, side, value):
 class TestVoxels:
     @image_comparison(['voxels-simple.png'], remove_text=True)
     def test_simple(self):
-        fig, ax = plt.subplots(subplot_kw={"projection": "3d"})
+        ax = plt.figure().add_subplot(projection="3d")
 
         x, y, z = np.indices((5, 4, 3))
         voxels = (x == y) | (y == z)
@@ -680,7 +677,7 @@ def test_simple(self):
     @image_comparison(['voxels-edge-style.png'],
                       remove_text=True, style='default')
     def test_edge_style(self):
-        fig, ax = plt.subplots(subplot_kw={"projection": "3d"})
+        ax = plt.figure().add_subplot(projection="3d")
 
         x, y, z = np.indices((5, 5, 4))
         voxels = ((x - 2)**2 + (y - 2)**2 + (z-1.5)**2) < 2.2**2
@@ -692,7 +689,7 @@ def test_edge_style(self):
     @image_comparison(['voxels-named-colors.png'], remove_text=True)
     def test_named_colors(self):
         """Test with colors set to a 3d object array of strings."""
-        fig, ax = plt.subplots(subplot_kw={"projection": "3d"})
+        ax = plt.figure().add_subplot(projection="3d")
 
         x, y, z = np.indices((10, 10, 10))
         voxels = (x == y) | (y == z)
@@ -705,7 +702,7 @@ def test_named_colors(self):
     @image_comparison(['voxels-rgb-data.png'], remove_text=True)
     def test_rgb_data(self):
         """Test with colors set to a 4d float array of rgb data."""
-        fig, ax = plt.subplots(subplot_kw={"projection": "3d"})
+        ax = plt.figure().add_subplot(projection="3d")
 
         x, y, z = np.indices((10, 10, 10))
         voxels = (x == y) | (y == z)
@@ -717,7 +714,7 @@ def test_rgb_data(self):
 
     @image_comparison(['voxels-alpha.png'], remove_text=True)
     def test_alpha(self):
-        fig, ax = plt.subplots(subplot_kw={"projection": "3d"})
+        ax = plt.figure().add_subplot(projection="3d")
 
         x, y, z = np.indices((10, 10, 10))
         v1 = x == y
@@ -735,7 +732,7 @@ def test_alpha(self):
 
     @image_comparison(['voxels-xyz.png'], tol=0.01)
     def test_xyz(self):
-        fig, ax = plt.subplots(subplot_kw={"projection": "3d"})
+        ax = plt.figure().add_subplot(projection="3d")
 
         def midpoints(x):
             sl = ()
@@ -770,7 +767,7 @@ def test_calling_conventions(self):
         x, y, z = np.indices((3, 4, 5))
         filled = np.ones((2, 3, 4))
 
-        fig, ax = plt.subplots(subplot_kw={"projection": "3d"})
+        ax = plt.figure().add_subplot(projection="3d")
 
         # all the valid calling conventions
         for kw in (dict(), dict(edgecolor='k')):
@@ -808,7 +805,7 @@ def test_line3d_set_get_data_3d():
 def test_inverted_cla():
     # Github PR #5450. Setting autoscale should reset
     # axes to be non-inverted.
-    fig, ax = plt.subplots(subplot_kw={"projection": "3d"})
+    ax = plt.figure().add_subplot(projection="3d")
     # 1. test that a new axis is not inverted per default
     assert not ax.xaxis_inverted()
     assert not ax.yaxis_inverted()
