Cleanup bar_stacked example.

anntzer · anntzer · commit 35c6027c196e · 2019-04-29T19:43:29.000+02:00
Use label=... to define legend labels (note that in the case here,
`plt.legend((p1[0], p2[0]), (..., ...))` is not even that nice as it
exposes the internals of the bar object, so using `label=...` is clearly
simpler).

Pep8ify variables.
diff --git a/examples/lines_bars_and_markers/bar_stacked.py b/examples/lines_bars_and_markers/bar_stacked.py
@@ -7,29 +7,28 @@
 using `~matplotlib.pyplot.bar`.  Note the parameters *yerr* used for
 error bars, and *bottom* to stack the women's bars on top of the men's
 bars.
-
 """
 
 import numpy as np
 import matplotlib.pyplot as plt
 
 
 N = 5
-menMeans = (20, 35, 30, 35, 27)
-womenMeans = (25, 32, 34, 20, 25)
-menStd = (2, 3, 4, 1, 2)
-womenStd = (3, 5, 2, 3, 3)
+men_means = [20, 35, 30, 35, 27]
+women_means = [25, 32, 34, 20, 25]
+men_std = [2, 3, 4, 1, 2]
+women_std = [3, 5, 2, 3, 3]
 ind = np.arange(N)    # the x locations for the groups
 width = 0.35       # the width of the bars: can also be len(x) sequence
 
-p1 = plt.bar(ind, menMeans, width, yerr=menStd)
-p2 = plt.bar(ind, womenMeans, width,
-             bottom=menMeans, yerr=womenStd)
+plt.bar(ind, men_means, width, yerr=men_std, label='Men')
+plt.bar(ind, women_means, width, yerr=women_std, bottom=men_means,
+        label='Women')
 
 plt.ylabel('Scores')
 plt.title('Scores by group and gender')
 plt.xticks(ind, ('G1', 'G2', 'G3', 'G4', 'G5'))
 plt.yticks(np.arange(0, 81, 10))
-plt.legend((p1[0], p2[0]), ('Men', 'Women'))
+plt.legend()
 
 plt.show()
