MNT: slightly simplify conditional in errorbar

tacaswell · tacaswell · commit e67b42b506a2 · 2015-12-22T17:43:51.000-05:00
This slightly simplifies the special casing of empty list in the
handling of xerr and yerr in errorbar
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -2890,10 +2890,8 @@ def xywhere(xs, ys, mask):
                 # above. This prevents Nx2 arrays from accidentally
                 # being accepted, when the user meant the 2xN transpose.
                 # special case for empty lists
-                if len(xerr) and not (len(xerr) == 1 or
-                                      (len(xerr) == len(x) and not (
-                                          iterable(xerr[0]) and
-                                          len(xerr[0]) > 1))):
+                if len(xerr) > 1 and not ((len(xerr) == len(x) and not (
+                        iterable(xerr[0]) and len(xerr[0]) > 1))):
                     raise ValueError("xerr must be a scalar, the same "
                                      "dimensions as x, or 2xN.")
                 # using list comps rather than arrays to preserve units
@@ -2955,10 +2953,8 @@ def xywhere(xs, ys, mask):
                          in cbook.safezip(y, yerr[1])]
             else:
                 # Check for scalar or symmetric, as in xerr.
-                if len(yerr) and not (len(yerr) == 1 or
-                                      (len(yerr) == len(y) and not (
-                                          iterable(yerr[0]) and
-                                          len(yerr[0]) > 1))):
+                if len(yerr) > 1 and not ((len(yerr) == len(y) and not (
+                        iterable(yerr[0]) and len(yerr[0]) > 1))):
                     raise ValueError("yerr must be a scalar, the same "
                                      "dimensions as y, or 2xN.")
                 # using list comps rather than arrays to preserve units
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -4106,8 +4106,10 @@ def test_errorbar_inputs_shotgun():
                                 [1, 1, 1, 1, 1],
                                 [[1, 1, 1, 1, 1],
                                  [1, 1, 1, 1, 1]],
+                                [[1]] * 5,
                                 np.ones(5),
                                 np.ones((2, 5)),
+                                np.ones((5, 1)),
                                 None
                                 ])
     xerr_cy = cycler('xerr', err_cycler)
