Make SubplotSpec.num2 never None.

anntzer · anntzer · commit 658bbd5ce27d · 2019-02-27T02:59:49.000+01:00
SubplotSpec.num2 == None is handled as if num2 was set to num1 (a
subplot spanning a single entry of a GridSpec).  Instead of having a
bunch of checks everywhere for that, just hide None behind a property.
diff --git a/lib/matplotlib/_constrained_layout.py b/lib/matplotlib/_constrained_layout.py
@@ -245,8 +245,6 @@ def _make_ghost_gridspec_slots(fig, gs):
             axs += [ax]
     for ax in axs:
         ss0 = ax.get_subplotspec()
-        if ss0.num2 is None:
-            ss0.num2 = ss0.num1
         hassubplotspec[ss0.num1:(ss0.num2 + 1)] = True
     for nn, hss in enumerate(hassubplotspec):
         if not hss:
@@ -342,8 +340,6 @@ def _align_spines(fig, gs):
 
     for n, ax in enumerate(axs):
         ss0 = ax.get_subplotspec()
-        if ss0.num2 is None:
-            ss0.num2 = ss0.num1
         rownummin[n], colnummin[n] = divmod(ss0.num1, ncols)
         rownummax[n], colnummax[n] = divmod(ss0.num2, ncols)
         width[n] = np.sum(
@@ -483,16 +479,12 @@ def _arrange_subplotspecs(gs, hspace=0, wspace=0):
     for child0 in sschildren:
         ss0 = child0.artist
         nrows, ncols = ss0.get_gridspec().get_geometry()
-        if ss0.num2 is None:
-            ss0.num2 = ss0.num1
         rowNum0min, colNum0min = divmod(ss0.num1, ncols)
         rowNum0max, colNum0max = divmod(ss0.num2, ncols)
         sschildren = sschildren[1:]
         for childc in sschildren:
             ssc = childc.artist
             rowNumCmin, colNumCmin = divmod(ssc.num1, ncols)
-            if ssc.num2 is None:
-                ssc.num2 = ssc.num1
             rowNumCmax, colNumCmax = divmod(ssc.num2, ncols)
             # OK, this tells us the relative layout of ax
             # with axc
diff --git a/lib/matplotlib/_layoutbox.py b/lib/matplotlib/_layoutbox.py
@@ -438,24 +438,13 @@ def layout_from_subplotspec(self, subspec,
         figLefts = [left + cellWs[2 * colNum] for colNum in range(ncols)]
         figRights = [left + cellWs[2 * colNum + 1] for colNum in range(ncols)]
 
-        rowNum, colNum = divmod(subspec.num1, ncols)
-        figBottom = figBottoms[rowNum]
-        figTop = figTops[rowNum]
-        figLeft = figLefts[colNum]
-        figRight = figRights[colNum]
-
-        if subspec.num2 is not None:
-
-            rowNum2, colNum2 = divmod(subspec.num2, ncols)
-            figBottom2 = figBottoms[rowNum2]
-            figTop2 = figTops[rowNum2]
-            figLeft2 = figLefts[colNum2]
-            figRight2 = figRights[colNum2]
-
-            figBottom = min(figBottom, figBottom2)
-            figLeft = min(figLeft, figLeft2)
-            figTop = max(figTop, figTop2)
-            figRight = max(figRight, figRight2)
+        rowNum1, colNum1 = divmod(subspec.num1, ncols)
+        rowNum2, colNum2 = divmod(subspec.num2, ncols)
+        figBottom = min(figBottoms[rowNum1], figBottoms[rowNum2])
+        figTop = max(figTops[rowNum1], figTops[rowNum2])
+        figLeft = min(figLefts[colNum1], figLefts[colNum2])
+        figRight = max(figRights[colNum1], figRights[colNum2])
+
         # These are numbers relative to 0,0,1,1.  Need to constrain
         # relative to parent.
 
diff --git a/lib/matplotlib/gridspec.py b/lib/matplotlib/gridspec.py
@@ -410,7 +410,7 @@ def __init__(self, gridspec, num1, num2=None):
         """
         The subplot will occupy the num1-th cell of the given
         gridspec.  If num2 is provided, the subplot will span between
-        num1-th cell and num2-th cell.
+        num1-th cell and num2-th cell *inclusive*.
 
         The index starts from 0.
         """
@@ -430,6 +430,17 @@ def __init__(self, gridspec, num1, num2=None):
         else:
             self._layoutbox = None
 
+    # num2 is a property only to handle the case where it is None and someone
+    # mutates num1.
+
+    @property
+    def num2(self):
+        return self.num1 if self._num2 is None else self._num2
+
+    @num2.setter
+    def num2(self, value):
+        self._num2 = value
+
     def __getstate__(self):
         state = self.__dict__
         try:
@@ -464,21 +475,15 @@ def get_rows_columns(self):
         gridspec = self.get_gridspec()
         nrows, ncols = gridspec.get_geometry()
         row_start, col_start = divmod(self.num1, ncols)
-        if self.num2 is not None:
-            row_stop, col_stop = divmod(self.num2, ncols)
-        else:
-            row_stop = row_start
-            col_stop = col_start
+        row_stop, col_stop = divmod(self.num2, ncols)
         return nrows, ncols, row_start, row_stop, col_start, col_stop
 
     def get_position(self, figure, return_all=False):
         """Update the subplot position from ``figure.subplotpars``.
         """
         gridspec = self.get_gridspec()
         nrows, ncols = gridspec.get_geometry()
-        rows, cols = np.unravel_index(
-            [self.num1] if self.num2 is None else [self.num1, self.num2],
-            (nrows, ncols))
+        rows, cols = np.unravel_index([self.num1, self.num2], (nrows, ncols))
         fig_bottoms, fig_tops, fig_lefts, fig_rights = \
             gridspec.get_grid_positions(figure)
 
