How It Works: Loops Within Loops

Given our example YAML configuration, calling migrate_objects() on a Migrator will cause it to:

• iterate through the source objects (rows), calling map() on the Mapper for each one

• every time map() is called on it, the Mapper creates a new target object, then iterates through its collection of Mappings, calling map() on each one

• the default Mapping objects just copy their attribute (column) value from the source object to the target object