Is there a builtin type in julia equivalent to python `None`?

[heliosdrm]

Related discussion:

On the arbitrariness of truth(iness)

Occasionally someone will be annoyed that Julia requires an actual true or false value in conditionals, whereas many dynamic languages (including Lisps) allow arbitrary values in conditions and have rules about what count as “truthy” or “falsey” in that context. Many static languages even allow a degree of this: C doesn’t have a boolean type and instead uses non-zero integer values to indicate truth and zero values to indicate false. Julia could easily do something along these lines by having a B…