plot_items: close figure if an exception occurs.

If any exception occurs in the process of creating the figure, we
don't want to leave an unfinished figure in pyplot's queue to be
displayed at some later time (the next time somebody calls
plt.show()).

Author: Benjamin Moody

wfdb/plot/plot.py

@@ -257,63 +257,73 @@ def plot_items(
 
     # Create figure
     fig, axes = create_figure(n_subplots, sharex, sharey, figsize)
+    try:
+        if signal is not None:
+            plot_signal(
+                signal,
+                sig_len,
+                n_sig,
+                fs,
+                time_units,
+                sig_style,
+                axes,
+                sampling_freq=sampling_freq,
+            )
 
-    if signal is not None:
-        plot_signal(
-            signal,
-            sig_len,
-            n_sig,
-            fs,
-            time_units,
-            sig_style,
-            axes,
-            sampling_freq=sampling_freq,
-        )
-
-    if ann_samp is not None:
-        plot_annotation(
-            ann_samp,
-            n_annot,
-            ann_sym,
-            signal,
-            n_sig,
-            fs,
-            time_units,
-            ann_style,
-            axes,
-            sampling_freq=sampling_freq,
-            ann_freq=ann_freq,
-        )
-
-    if ecg_grids:
-        plot_ecg_grids(
-            ecg_grids,
-            fs,
-            sig_units,
-            time_units,
-            axes,
-            sampling_freq=sampling_freq,
-        )
-
-    # Add title and axis labels.
-    # First, make sure that xlabel and ylabel inputs are valid
-    if xlabel:
-        if len(xlabel) != signal.shape[1]:
-            raise Exception(
-                "The length of the xlabel must be the same as the "
-                "signal: {} values".format(signal.shape[1])
+        if ann_samp is not None:
+            plot_annotation(
+                ann_samp,
+                n_annot,
+                ann_sym,
+                signal,
+                n_sig,
+                fs,
+                time_units,
+                ann_style,
+                axes,
+                sampling_freq=sampling_freq,
+                ann_freq=ann_freq,
             )
 
-    if ylabel:
-        if len(ylabel) != n_subplots:
-            raise Exception(
-                "The length of the ylabel must be the same as the "
-                "signal: {} values".format(n_subplots)
+        if ecg_grids:
+            plot_ecg_grids(
+                ecg_grids,
+                fs,
+                sig_units,
+                time_units,
+                axes,
+                sampling_freq=sampling_freq,
             )
 
-    label_figure(
-        axes, n_subplots, time_units, sig_name, sig_units, xlabel, ylabel, title
-    )
+        # Add title and axis labels.
+        # First, make sure that xlabel and ylabel inputs are valid
+        if xlabel:
+            if len(xlabel) != signal.shape[1]:
+                raise Exception(
+                    "The length of the xlabel must be the same as the "
+                    "signal: {} values".format(signal.shape[1])
+                )
+
+        if ylabel:
+            if len(ylabel) != n_subplots:
+                raise Exception(
+                    "The length of the ylabel must be the same as the "
+                    "signal: {} values".format(n_subplots)
+                )
+
+        label_figure(
+            axes,
+            n_subplots,
+            time_units,
+            sig_name,
+            sig_units,
+            xlabel,
+            ylabel,
+            title,
+        )
+    except BaseException:
+        plt.close(fig)
+        raise
 
     if return_fig:
         return fig