pushd context manager

manage.py

@contextmanager
def pushd(new_dir):
    """
    A context manager that implements the `pushd` command, letting you run a
    block of commands while in a different directory
    """
    old_dir = os.getcwd()
    os.chdir(new_dir)
    try:
        yield old_dir
    finally:
        os.chdir(old_dir)