Reload Package in Active Development (IPython Notebook)

function

import sys
import types

import dev_package

def reload_package(root_module):
    package_name = root_module.__name__

    # get a reference to each loaded module
    loaded_package_modules = dict([
        (key, value) for key, value in sys.modules.items() 
        if key.startswith(package_name) and isinstance(value, types.ModuleType)])

    # delete references to these loaded modules from sys.modules
    for key in loaded_package_modules:
        del sys.modules[key]

    # load each of the modules again; 
    # make old modules share state with new modules
    for key in loaded_package_modules:
        print 'loading %s' % key
        newmodule = __import__(key)
        oldmodule = loaded_package_modules[key]
        oldmodule.__dict__.clear()
        oldmodule.__dict__.update(newmodule.__dict__)
        
reload_package(dev_package)