fixed code to display plots given as arrays of plotting axes (as returned by .plot(subplots=True))

gdementen · gdementen · commit 2ec38972531c · 2020-03-31T12:09:54.000+02:00
* avoid an exception whenever we try to display any empty sequence (whether it contains plots or not)
* avoid copying the whole sequence just to get the first element for non array sequences. This loose the ability to display plots
  hidden in nested sequences (instead of ndarrays) but I am unsure doing that even for simple sequences is useful anyway
diff --git a/doc/source/changes/version_0_32_2.rst.inc b/doc/source/changes/version_0_32_2.rst.inc
@@ -1,4 +1,4 @@
-﻿.. py:currentmodule:: larray_editor
+.. py:currentmodule:: larray_editor
 
 Syntax changes
 ^^^^^^^^^^^^^^
@@ -38,4 +38,4 @@ Miscellaneous improvements
 Fixes
 ^^^^^
 
-* fixed something (closes :editor_issue:`1`).
+* fixed spurious warning in the console when an expression results in an empty sequence (array, list, tuple).
diff --git a/larray_editor/editor.py b/larray_editor/editor.py
@@ -694,15 +694,24 @@ def ipython_cell_executed(self):
                 # last command. Which means that if the last command did not produce any output, _ is not modified.
                 cur_output = user_ns['_oh'].get(cur_input_num)
                 if cur_output is not None:
+                    if 'inline' not in matplotlib.get_backend():
+                        if isinstance(cur_output, np.ndarray) and cur_output.size > 0:
+                            first_output = cur_output.flat[0]
+                            if isinstance(first_output, matplotlib.axes.Subplot):
+                                show_figure(self, first_output.figure)
+                        # we use a different path for sequences than for arrays to avoid copying potentially
+                        # big non-array sequences using np.ravel(). This code does not support nested sequences,
+                        # but I am already unsure supporting simple non-array sequences is useful.
+                        elif isinstance(cur_output, collections.Sequence) and len(cur_output) > 0:
+                            first_output = cur_output[0]
+                            if isinstance(first_output, matplotlib.axes.Subplot):
+                                show_figure(self, first_output.figure)
+                        elif isinstance(cur_output, matplotlib.axes.Subplot):
+                            show_figure(self, cur_output.figure)
+
                     if self._display_in_grid('<expr>', cur_output):
                         self.view_expr(cur_output)
 
-                    if isinstance(cur_output, collections.Iterable):
-                        cur_output = np.ravel(cur_output)[0]
-
-                    if isinstance(cur_output, matplotlib.axes.Subplot) and 'inline' not in matplotlib.get_backend():
-                        show_figure(self, cur_output.figure)
-
     def on_selection_changed(self):
         selected = self._listwidget.selectedItems()
         if selected:
