Exploration of failed tests

Author: nicolas.rebena

pandas/plotting/_core.py

@@ -1229,7 +1229,8 @@ def __init__(self, data, **kwargs):
                 self.tickoffset = self.bar_width * pos
                 self.lim_offset = 0
 
-        self.ax_pos = self.data.index._mpl_repr()
+        self.ax_pos = self.tick_pos - self.tickoffset
+        self.ax_index = self.data.index._mpl_repr()
 
     def _args_adjust(self):
         if is_list_like(self.bottom):
@@ -1278,30 +1279,34 @@ def _make_plot(self):
 
             if self.subplots:
                 w = self.bar_width / 2
-                rect = self._plot(ax, self.ax_pos, y, self.bar_width,
+                rect = self._plot(ax, self.ax_index, y, self.bar_width,
                                   start=start, label=label,
                                   log=self.log, **kwds)
                 ax.set_title(label)
             elif self.stacked:
                 mask = y > 0
                 start = np.where(mask, pos_prior, neg_prior) + self._start_base
                 w = self.bar_width / 2
-                rect = self._plot(ax, self.ax_pos, y, self.bar_width,
+                rect = self._plot(ax, self.ax_index, y, self.bar_width,
                                   start=start, label=label,
                                   log=self.log, **kwds)
                 pos_prior = pos_prior + np.where(mask, y, 0)
                 neg_prior = neg_prior + np.where(mask, 0, y)
             else:
                 w = self.bar_width / K
                 # TODO: Test if this is the expected solution
-                rect = self._plot(ax, self.ax_pos, y, w,
+                rect = self._plot(ax, self.ax_index, y, w,
                                   start=start, label=label,
                                   log=self.log, **kwds)
             self._add_legend_handle(rect, label, index=i)
 
     def _post_plot_logic(self, ax, data):
         name = self._get_index_name()
 
+        s_edge = self.ax_pos[0] - 0.25 + self.lim_offset
+        e_edge = self.ax_pos[-1] + 0.25 + self.bar_width + self.lim_offset
+        ax.set_xlim((s_edge, e_edge))
+
         if name is not None and self.use_index:
             ax.set_xlabel(name)
 

pandas/tests/plotting/mytest.py

@@ -0,0 +1,23 @@
+# https://github.com/pandas-dev/pandas/issues/26186
+import pandas as pd
+import matplotlib.pyplot as plt
+
+data = {"A":0, "B":3, "C":-4}
+df = pd.DataFrame.from_dict(data, orient = "index", columns = ["Value"])
+fig = plt.figure()
+ax = plt.gca()
+ax = df.plot.bar(ax = ax)
+
+df2 = df.sort_values("Value") * - 2
+df2.plot.bar(ax = ax, color = "red")
+plt.show()
+
+fig = plt.figure(num='purepyplot')
+plt.bar(df.index.values, df.Value.values)
+ax = plt.gca()
+ax.bar(df2.index.values, df2.Value.values)
+plt.show()
+
+import tests.plotting.test_frame as tf 
+T = tf.TestDataFramePlots()
+T.test_bar_align_single_column()

pandas/tests/plotting/test_frame.py

@@ -1341,6 +1341,9 @@ def _check_bar_alignment(self, df, kind='bar', stacked=False,
                 raise ValueError
 
             # Check the ticks locates on integer
+            print(axis.get_ticklocs())
+            print([x.get_text() for x in  axis.get_ticklabels()])
+            print(np.arange(len(df)))
             assert (axis.get_ticklocs() == np.arange(len(df))).all()
 
             if align == 'center':