根据给定的对象路径，动态加载对象。

def import_from_string(path, slient=True):
    """
    根据给定的对象路径，动态加载对象。
    """
    names = path.split(".")
    for i in range(len(names), 0, -1):
        p1 = ".".join(names[0:i])
        module = import_module(p1)
        if module:
            p2 = ".".join(names[i:])
            if p2:
                return select(module, p2, slient=slient)
            else:
                return module
    name = names[0]
    names = names[1:]
    module = get_caller_locals().get(name)
    if module and names:
        return select(module, ".".join(names), slient=slient)
    if module:
        return module
    module = get_caller_globals().get(name)
    if module and names:
        return select(module, ".".join(names), slient=slient)
    if module:
        return module
    if slient:
        return None
    else:
        raise ImportError("Import {path} failed.".format(path=path))