def _maybe_fill(arr, fill_value=np.nan):
 if _is_na_compat(arr, fill_value):
  arr.fill(fill_value)
 return arr

def _maybe_fill ( arr , fill_value = np . nan ) : if _is_na_compat ( arr , fill_value ) : arr . fill ( fill_value ) return arr
if we have a compatiable fill_value and arr dtype .