Silence more warnings, engine='flox' (#198)

Author: dcherian

flox/aggregate_flox.py

@@ -107,13 +107,15 @@ def mean(group_idx, array, *, axis=-1, size=None, fill_value=None, dtype=None):
     if fill_value is None:
         fill_value = 0
     out = sum(group_idx, array, axis=axis, size=size, dtype=dtype, fill_value=fill_value)
-    out /= nanlen(group_idx, array, size=size, axis=axis, fill_value=0)
+    with np.errstate(invalid="ignore", divide="ignore"):
+        out /= nanlen(group_idx, array, size=size, axis=axis, fill_value=0)
     return out
 
 
 def nanmean(group_idx, array, *, axis=-1, size=None, fill_value=None, dtype=None):
     if fill_value is None:
         fill_value = 0
     out = nansum(group_idx, array, size=size, axis=axis, dtype=dtype, fill_value=fill_value)
-    out /= nanlen(group_idx, array, size=size, axis=axis, fill_value=0)
+    with np.errstate(invalid="ignore", divide="ignore"):
+        out /= nanlen(group_idx, array, size=size, axis=axis, fill_value=0)
     return out