traitlets.py 文件源码

def _deprecated_method(method, cls, method_name, msg):
    """Show deprecation warning about a magic method definition.

    Uses warn_explicit to bind warning to method definition instead of triggering code,
    which isn't relevant.
    """
    warn_msg = "{classname}.{method_name} is deprecated: {msg}".format(
        classname=cls.__name__, method_name=method_name, msg=msg
    )

    for parent in inspect.getmro(cls):
        if method_name in parent.__dict__:
            cls = parent
            break
    try:
        fname = inspect.getsourcefile(method) or "<unknown>"
        lineno = inspect.getsourcelines(method)[1] or 0
    except (IOError, TypeError) as e:
        # Failed to inspect for some reason
        warn(warn_msg + ('\n(inspection failed) %s' % e), DeprecationWarning)
    else:
        warn_explicit(warn_msg, DeprecationWarning, fname, lineno)