define a virtual module

virutal_module.py

import types

class VirtualModule(types.ModuleType):
    def __init__(self, module_name, sub_modules):

        super().__init__(module_name)
        try:
            import sys
            sys.modules[module_name] = self
            self._module_name = module_name
            self._sub_modules = sub_modules
            for sub_name, module in sub_modules.items():
                sys.modules[f"{module_name}.{sub_name}"] = module
        except ImportError as err:
            raise err  # please signal error in some useful way :-)

    def __repr__(self):
        return "Virtual module for " + self._module_name

    def __getattr__(self, attrname):

        if attrname in self._sub_modules.keys():
            import sys
            return self._sub_modules[attrname]
        else:
            return super().__getattr__(attrname)
          
# usage

import numpy 

VirtualModule("base", {"child": numpy})

import base.child as x 
import base 
base.child