Support passing spine bounds as single tuple.

anntzer · anntzer · commit e06d2bc333ee · 2019-07-30T11:37:26.000+02:00
For consistency with Axes.set_xlim.

There's no test whatsoever for Spine.set_bounds, but we can at least
exercise that code path in the examples.
diff --git a/examples/ticks_and_spines/spines_bounds.py b/examples/ticks_and_spines/spines_bounds.py
@@ -27,7 +27,7 @@
 ax.set_yticks([-1, 0, 1])
 
 # Only draw spine between the y-ticks
-ax.spines['left'].set_bounds(-1, 1)
+ax.spines['left'].set_bounds((-1, 1))
 # Hide the right and top spines
 ax.spines['right'].set_visible(False)
 ax.spines['top'].set_visible(False)
diff --git a/lib/matplotlib/axes/_base.py b/lib/matplotlib/axes/_base.py
@@ -3106,7 +3106,7 @@ def set_xlim(self, left=None, right=None, emit=True, auto=False,
             The left xlim in data coordinates. Passing *None* leaves the
             limit unchanged.
 
-            The left and right xlims may be passed as the tuple
+            The left and right xlims may also be passed as the tuple
             (*left*, *right*) as the first positional argument (or as
             the *left* keyword argument).
 
@@ -3486,7 +3486,7 @@ def set_ylim(self, bottom=None, top=None, emit=True, auto=False,
             The bottom ylim in data coordinates. Passing *None* leaves the
             limit unchanged.
 
-            The bottom and top ylims may be passed as the tuple
+            The bottom and top ylims may also be passed as the tuple
             (*bottom*, *top*) as the first positional argument (or as
             the *bottom* keyword argument).
 
diff --git a/lib/matplotlib/spines.py b/lib/matplotlib/spines.py
@@ -534,11 +534,33 @@ def get_spine_transform(self):
         else:
             raise ValueError("unknown spine_transform type: %s" % what)
 
-    def set_bounds(self, low, high):
-        """Set the bounds of the spine."""
+    def set_bounds(self, low=None, high=None):
+        """
+        Set the spine bounds.
+
+        .. ACCEPTS: (low: float, high: float)
+
+        Parameters
+        ----------
+        low : scalar, optional
+            The lower spine bound. Passing *None* leaves the limit unchanged.
+
+            The bounds may also be passed as the tuple (*low*, *high*) as the
+            first positional argument.
+
+        high : scalar, optional
+            The higher spine bound. Passing *None* leaves the limit unchanged.
+        """
         if self.spine_type == 'circle':
             raise ValueError(
                 'set_bounds() method incompatible with circular spines')
+        if high is None and np.iterable(low):
+            low, high = low
+        old_low, old_high = self.get_bounds() or (None, None)
+        if low is None:
+            low = old_low
+        if high is None:
+            high = old_high
         self._bounds = (low, high)
         self.stale = True
 
