Fix no legend error message and duplicate labels (#45)

asreviewcontrib/makita/templates/script_get_plot.py.template

@@ -26,61 +26,63 @@ from asreview import open_state
 from asreviewcontrib.insights.plot import plot_recall
 
 
-def get_plot_from_states(states, filename, legend=None):
-    """Generate an ASReview plot from state files."""
+def _set_legend(ax, state, legend_option, label_to_line, state_file):
+    metadata = state.settings_metadata
+    label = None
+
+    if legend_option == "filename":
+        label = state_file.stem
+    elif legend_option == "model":
+        label = " - ".join(
+            [metadata["settings"]["model"],
+             metadata["settings"]["feature_extraction"],
+             metadata["settings"]["balance_strategy"],
+             metadata["settings"]["query_strategy"]])
+    elif legend_option == "classifier":
+        label = metadata["settings"]["model"]
+    else:
+        try:
+            label = metadata["settings"][legend_option]
+        except KeyError as err:
+            raise ValueError(f"Invalid legend setting: '{legend_option}'") from err  # noqa: E501
+
+    if label:
+        # add label to line
+        if label not in label_to_line:
+            ax.lines[-2].set_label(label)
+            label_to_line[label] = ax.lines[-2]
+        # set color of line to the color of the first line with the same label
+        else:
+            ax.lines[-2].set_color(label_to_line[label].get_color())
+            ax.lines[-2].set_label("_no_legend_")
 
-    # sort the states alphabetically
-    states = sorted(states)
 
+def get_plot_from_states(states, filename, legend=None):
+    """Generate an ASReview plot from state files.
+
+    Arguments
+    ---------
+    states: list
+        List of state files.
+    filename: str
+        Filename of the plot.
+    legend: str
+        Add a legend to the plot, based on the given parameter.
+        Possible values: "filename", "model", "feature_extraction",
+        "balance_strategy", "query_strategy", "classifier".
+    """
+    states = sorted(states)
     fig, ax = plt.subplots()
-
-    labels = []
+    label_to_line = {}
 
     for state_file in states:
         with open_state(state_file) as state:
-            # draw the plot
             plot_recall(ax, state)
+            if legend:
+                _set_legend(ax, state, legend, label_to_line, state_file)
 
-            # settings for legend "filename"
-            if legend == "filename":
-                ax.lines[-2].set_label(state_file.stem)
-                ax.legend(loc=4, prop={'size': 8})
-            # settings for legend "settings"
-            elif legend:
-                metadata = state.settings_metadata
-
-                # settings for legend "model"
-                if legend == "model":
-                    label = " - ".join(
-                            [metadata["settings"]["model"],
-                             metadata["settings"]["feature_extraction"],
-                             metadata["settings"]["balance_strategy"],
-                             metadata["settings"]["query_strategy"]])
-
-                # settings for legend "classifier"
-                elif legend == "classifier":
-                    label = metadata["settings"]["model"]
-
-                # settings for legend from metadata
-                else:
-                    try:
-                        label = metadata["settings"][legend]
-                    except KeyError as exc:
-                        raise ValueError(
-                            f"Legend setting '{legend}' "
-                            "not found in state file settings."
-                        ) from exc
-
-                # add label to legend if not already present 
-                # (multiple states can have the same label)
-                if label not in labels:
-                    ax.lines[-2].set_label(label)
-                    labels.append(label)
-
-    # add legend to plot
-    ax.legend(loc=4, prop={'size': 8})
-
-    # save plot
+    if legend:
+        ax.legend(loc=4, prop={'size': 8})
     fig.savefig(str(filename))