Lazy Importing

importing.py

class lazy_import(object):
    """
    The main purpose for this is to make module level coverage work :(
    If/When nose2 figures out how to fix the coverage problem, or if
    a new test discovery method or loader is used, this should be removed
    in favor of real imports.
    """
    def __init__(self, python_path):
        self.python_path = python_path
        self._obj = None

    def _do_import(self):
        parts = self.python_path.split('.')
        module_path = '.'.join(parts[:-1])
        obj = parts[-1]
        module = __import__(module_path, globals(), locals(), fromlist=[obj])
        self._obj = getattr(module, obj)

    def __call__(self, *args, **kwargs):
        if self._obj is None:
            self._do_import()
        return self._obj(*args, **kwargs)

    def __getattr__(self, item):
        if self._obj is None:
            self._do_import()
        return getattr(self._obj, item)