ž 7’Re c@sWdZddlmZmZmZddlZddlmZiZddd„Z dS(u€A collection of modules for iterating through different kinds of tree, generating tokens identical to those produced by the tokenizer module. To create a tree walker for a new type of tree, you need to do implement a tree walker object (called TreeWalker by convention) that implements a 'serialize' method taking a tree as sole argument and returning an iterator generating tokens. i(uabsolute_importudivisionuunicode_literalsNi(u default_etreecKs|jƒ}|tkrú|d kr[dt|f}t|ƒtj|}|jt| s