Fix issue when converting matplotlib lines+markers legend to plotly

plotly/matplotlylib/renderer.py

@@ -299,7 +299,7 @@ def draw_bar(self, coll):
         )  # TODO ditto
         if len(bar["x"]) > 1:
             self.msg += "    Heck yeah, I drew that bar chart\n"
-            (self.plotly_fig.add_trace(bar),)
+            self.plotly_fig.add_trace(bar)
             if bar_gap is not None:
                 self.plotly_fig["layout"]["bargap"] = bar_gap
         else:
@@ -370,6 +370,12 @@ def draw_legend_shapes(self, mode, shape, **props):
                 x1 = props["data"][1][0]
                 y1 = props["data"][1][1]
 
+                lines_shape = shape.copy()
+                ignored_props = ["symbol", "size"]
+                for prop in ignored_props:
+                    if prop in lines_shape:
+                        lines_shape.pop(prop)
+
                 legend_shape = go.layout.Shape(
                     type=mode,
                     xref="paper",
@@ -378,7 +384,7 @@ def draw_legend_shapes(self, mode, shape, **props):
                     y0=y + 0.02,
                     x1=x1,
                     y1=y1 + 0.02,
-                    **shape,
+                    **lines_shape,
                 )
             else:
                 self.msg += "not sure how to handle this element\n"
@@ -497,7 +503,7 @@ def draw_marked_line(self, **props):
                 marked_line["x"] = mpltools.mpl_dates_to_datestrings(
                     marked_line["x"], formatter
                 )
-            (self.plotly_fig.add_trace(marked_line),)
+            self.plotly_fig.add_trace(marked_line)
             self.msg += "    Heck yeah, I drew that line\n"
         elif props["coordinates"] == "axes":
             # dealing with legend graphical elements

plotly/matplotlylib/tests/__init__.py

@@ -0,0 +1,4 @@
+import matplotlib
+
+matplotlib.use("Agg")
+import matplotlib.pyplot as plt

plotly/matplotlylib/tests/test_renderer.py

@@ -0,0 +1,19 @@
+import plotly.tools as tls
+
+from . import plt
+
+
+def test_lines_markers_legend_plot():
+    x = [0, 1]
+    y = [0, 1]
+    label = "label"
+    plt.figure()
+    plt.plot(x, y, "o-", label=label)
+    plt.legend()
+
+    plotly_fig = tls.mpl_to_plotly(plt.gcf())
+
+    assert plotly_fig.data[0].mode == "lines+markers"
+    assert plotly_fig.data[0].x == tuple(x)
+    assert plotly_fig.data[0].y == tuple(y)
+    assert plotly_fig.data[0].name == "label"