BUG: Fixed plot label shows as None. #8905

Author: dxe4

doc/source/whatsnew/v0.15.2.txt

@@ -122,6 +122,7 @@ Bug Fixes
 - Bug in ``merge`` where ``how='left'`` and ``sort=False`` would not preserve left frame order (:issue:`7331`)
 
 - Fix negative step support for label-based slices (:issue:`8753`)
+- Fixed given label showing as None (:issue:`#8905`)
 
   Old behavior:
 

pandas/tools/plotting.py

@@ -1589,7 +1589,9 @@ def _make_plot(self):
             errors = self._get_errorbars(label=label, index=i)
             kwds = dict(kwds, **errors)
 
-            label = com.pprint_thing(label)  # .encode('utf-8')
+            if label is not None or self.legend:
+                label = com.pprint_thing(label)  # .encode('utf-8')
+
             kwds['label'] = label
 
             newlines = plotf(ax, x, y, style=style, column_num=i, **kwds)
@@ -2283,7 +2285,7 @@ def _plot(data, x=None, y=None, subplots=False,
                 if com.is_integer(y) and not data.columns.holds_integer():
                     y = data.columns[y]
                 label = x if x is not None else data.index.name
-                label = kwds.pop('label', label)
+                label = kwds.get('label', label)
                 series = data[y].copy()  # Don't modify
                 series.index.name = label
 

pandas/tseries/tests/test_plotting.py

@@ -89,6 +89,20 @@ def test_nonnumeric_exclude(self):
 
         self.assertRaises(TypeError, df['A'].plot)
 
+    @slow
+    def test_legend_added(self):
+        df = DataFrame(np.random.rand(2, 4), columns=['a', 'b', 'c', 'd'])
+        a_plot = df.plot(kind='scatter', x='a', y='b',
+                         color='DarkBlue', label='Label')
+        b_plot = df.plot(kind='line', x='a', y='b',
+                         color='DarkBlue', label="foo")
+        c_plot = df.plot(kind='line', x='a', y='b',
+                         color='DarkBlue', label=None, legend=False)
+
+        self.assertEqual(a_plot.legend().texts[0].get_text(), 'Label')
+        self.assertEqual(b_plot.legend().texts[0].get_text(), 'foo')
+        self.assertEqual(c_plot.legend(), None)
+
     @slow
     def test_tsplot(self):
         from pandas.tseries.plotting import tsplot