pytype crashes with syntax error on del statement

[markshannon]

This is causing the typeshed CI to reject the following valid code:
https://github.com/markshannon/typeshed/blob/362bedecd9778196e44d4c88acc39313bb38a6ba/stdlib/2/os/path.pyi

[matthiaskramm]

So far, we have put an underscore in front of classes or types that are internal to a module. The advantage is that sometimes you do need to refer to an (internal) class of a module from a different pyi.

In the example of path.pyi, the internal type is a Union. Maybe we just shouldn't export union types from pyi, by default? Do we have any use cases where you'd actually want to declare a union in one pyi, but use it in another?

[rchen152]

Typeshed's convention is still to prefix the names of typing constructs with an underscore; it's unlikely that pytype's parser will ever (intentionally) support del.