There is a collection of nodes used to represent assignments. Each
assignment statement in the source code becomes a single
Assign node in the AST. The nodes attribute is a
list that contains a node for each assignment target. This is
necessary because assignment can be chained, e.g. a = b = 2.
Each Node in the list will be one of the following classes:
AssAttr, AssList, AssName, or
AssTuple.
Each target assignment node will describe the kind of object being
assigned to: AssName for a simple name, e.g. a = 1.
AssAttr for an attribute assigned, e.g. a.x = 1.
AssList and AssTuple for list and tuple expansion
respectively, e.g. a, b, c = a_tuple.
The target assignment nodes also have a flags attribute that indicates whether the node is being used for assignment or in a delete statement. The AssName is also used to represent a delete statement, e.g. del x.
When an expression contains several attribute references, an assignment or delete statement will contain only one AssAttr node - for the final attribute reference. The other attribute references will be represented as Getattr nodes in the expr attribute of the AssAttr instance.