how to instantiate a python class from a string using imp.

load_class.py

import imp

def load_class(full_class_string):
    """
    Dynamically load a class from a string
    
    >>> klass = load_class("module.submodule.ClassName")
    >>> klass2 = load_class("myfile.Class2")

    """
    class_data = full_class_string.split(".")
    
    module_str = class_data[0]
    class_str = class_data[-1]
    submodules_list = []

    if len(class_data) > 2:
        submodules_list = class_data[1:-1]

    f, filename, description = imp.find_module(module_str)
    module = imp.load_module(module_str, f, filename, description)
    
    # Find each submodule
    for smod in submodules_list:
        path = os.path.dirname(filename) if os.path.isfile(filename) else filename

        f, filename, description = imp.find_module(smod, [path])
        
        # Now we can load the module
        try:
            module = imp.load_module(" ".join(class_data[:-1]), f, filename, description)
        finally:
            if f:
                f.close()

    # Finally, we retrieve the Class
    return getattr(module, class_str)