Merge pull request #399 from lgray/fix_394_backport

Backport of #398

coffea/hist/hist_tools.py

@@ -954,6 +954,8 @@ def fill(self, **values):
         weight = values.pop("weight", None)
         if isinstance(weight, (awkward1.Array, np.ndarray)):
             weight = coffea.util._ensure_flat(weight)
+        if isinstance(weight, numbers.Number):
+            weight = np.atleast_1d(weight)
         if not all(d.name in values for d in self._axes):
             missing = ", ".join(d.name for d in self._axes if d.name not in values)
             raise ValueError("Not all axes specified for %r.  Missing: %s" % (self, missing))

tests/test_hist_tools.py

@@ -265,3 +265,7 @@ def test_issue_333():
     axis = hist.Bin("channel", "Channel b1", 50, 0, 2000)
     temp = np.arange(0, 2000, 40, dtype=np.int16)
     assert np.all(axis.index(temp) == np.arange(50) + 1)
+
+def test_issue_394():
+    dummy = hist.Hist("Dummy" , hist.Cat("sample", "sample"), hist.Bin("dummy", "Number of events", 1, 0, 1))
+    dummy.fill(sample="test", dummy=1, weight=0.5)