http://docs.python.org/2/library/ast.html

AST module doc is incomplete. To write node visitor, you need to know possible types of parameters and expected values for every node type. They are different.

http://hg.python.org/cpython/file/1ee45eb6aab9/Parser/Python.asdl

For example, visit_Assign expects:
 Assign(targets, value)
   `targets` can be List, Tuple or Name

When there is List, and when there is Tuple? It should be documented.

The node types are all listed right there in the docs in the abstract grammar section, so arguing they are incomplete I don't think is accurate.

I'm willing to leave this open in case some ambitious person wants to write docs for every node type, but I think this is a very low priority task.

Neither you nor docs answer the question when Assign node gets Tuple as argument, when List and when Subscript.

While it is obvious to you, I personally don't know what a Subscript is. This is the kind of stuff that I'd like to see documented.

http://stackoverflow.com/questions/8370132/what-syntax-is-represented-by-an-extslice-node-in-pythons-ast

https://greentreesnakes.readthedocs.org/en/latest/

When citing a link, it's customary to give at least a comment *why* you are citing it.

SO link serves a proof that a problem is actual. It is needed, because, for example Brett doesn't think it is important.

2nd link is the same proof, and also an example of documentation wanted.

In fact it may be the documentation that could be merged.

@pablogsal is working on documenting nodes (not every node type that exists, the ones that aren't deprecated) in PR 17812

@BTaskaya, thank you.  I'm going to close this issue as a duplicate of that one.