ENH: support integers as (in addition to strings)

tacaswell · tacaswell · commit 1939911da2da · 2020-02-29T19:12:28.000-05:00
diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
@@ -1584,7 +1584,7 @@ def build_grid(self, layout, *, subplot_kw=None, gridspec_kw=None,
 
         Parameters
         ----------
-        layout : list of list of str
+        layout : list of list of {str, int,  Axes} or nested
 
             A visual layout of how you want your Axes to be arranged
             labeled as strings.  For example ::
@@ -1629,7 +1629,7 @@ def _process_layout(layout):
                 for k, v in enumerate(row):
                     if v == empty_sentinal:
                         continue
-                    elif isinstance(v, (str, Axes)):
+                    elif isinstance(v, (int, str, Axes)):
                         unique_ids.add(v)
                     else:
                         nested[(j, k)] = v
@@ -1654,13 +1654,16 @@ def _do_layout(gs, layout, unique_ids, nested):
                 covered[slc] = True
                 if name == empty_sentinal:
                     continue
-                if isinstance(name, str):
-                    output[name] = self.add_subplot(gs[slc], **subplot_kw)
-                else:
+
+                if hasattr(name, 'set_subplotspec'):
                     ax = name
                     ax.set_subplotspec(gs[slc])
                     ax.update_params()
                     ax.set_position(ax.figbox)
+                    output[id(ax)] = ax
+                else:
+                    output[name] = self.add_subplot(
+                        gs[slc], **subplot_kw)
 
             for (j, k), layout in nested.items():
                 layout = np.asarray(layout)
@@ -1672,7 +1675,7 @@ def _do_layout(gs, layout, unique_ids, nested):
                 output.update(nested_output)
             return output
 
-        layout = np.asarray(layout)
+        layout = np.asarray(layout, dtype=object)
         rows, cols = layout.shape
         gs = GridSpec(rows, cols, figure=self, **gridspec_kw)
         return _do_layout(gs, layout, *_process_layout(layout))
