To chain calls on children packages and modules, how about importing children of packages from the package’s init module?
package
init.py
import childpackage
childpackage
init.py
import childmodule
Result:
import package
package.childpackage.childmodule.any_method_inside_childmodule()
I tend to treat the init as an opportuity to tailor the interface of any package, so as to simplify any of its content that may be irrelevant for the end user.