Why? not x means x isNoneorlen(x) == 0 for lists. len(x) == 0 will raise an exception if x is None. In most cases, the distinction between None and [] isn’t important, and if it is, I’d expect separate checks for those (again, for explicitness) since you’d presumably handle each case differently.
In short:
if the distinction between None and [] is important, have separate checks
if not, not x should be your default, since that way it’s a common pattern for all types
Why?
not xmeansx is None or len(x) == 0for lists.len(x) == 0will raise an exception ifxis None. In most cases, the distinction betweenNoneand[]isn’t important, and if it is, I’d expect separate checks for those (again, for explicitness) since you’d presumably handle each case differently.In short:
Noneand[]is important, have separate checksnot xshould be your default, since that way it’s a common pattern for all types