Triplot duplicated label (matplotlib#23813)

* label removed

* Test for triplot duplicated label

* NewLine at end of file (flake 8)

* Flake 8 compliant

* Explicit logic test

Author: amartinez1224

lib/matplotlib/tests/test_triangulation.py

@@ -1299,3 +1299,15 @@ def test_triplot_with_ls(fig_test, fig_ref):
     data = [[0, 1, 2]]
     fig_test.subplots().triplot(x, y, data, ls='--')
     fig_ref.subplots().triplot(x, y, data, linestyle='--')
+
+
+def test_triplot_label():
+    x = [0, 2, 1]
+    y = [0, 0, 1]
+    data = [[0, 1, 2]]
+    fig, ax = plt.subplots()
+    lines, markers = ax.triplot(x, y, data, label='label')
+    handles, labels = ax.get_legend_handles_labels()
+    assert labels == ['label']
+    assert len(handles) == 1
+    assert handles[0] is lines

lib/matplotlib/tri/triplot.py

@@ -77,6 +77,7 @@ def triplot(ax, *args, **kwargs):
         **kw,
         'linestyle': 'None',  # No line to draw.
     }
+    kw_markers.pop('label', None)
     if marker not in [None, 'None', '', ' ']:
         tri_markers = ax.plot(x, y, **kw_markers)
     else: