python - 如何以正确的方式使用默认值

Question

给定以下函数:

def httpstatus(self, url, data=None, timeout=None):
    if timeout is None:
        timeout = socket._GLOBAL_DEFAULT_TIMEOUT
    urlopen(url, data, timeout)

超时参数应该是可选的。但如果省略，我想使用 socket._GLOBAL_DEFAULT_TIMEOUT 值，如代码所示。但是，那个是 protected 成员。这似乎不是正确的方法。如此不同的方法...

def httpstatus(self, url, data=None, timeout=None):
    if timeout is None:
        urlopen(url, data)
    else:
        urlopen(url, data, timeout)

哎呀那个更脏...

回退到套接字默认超时的正确方法是什么？

Answer 1

您可以使用 **-syntax为此:

def httpstatus(self, url, data=None, timeout=None):
    kwargs = {}
    if timeout is not None:
        kwargs['timeout'] = timeout
    urlopen(url, data, **kwargs)

甚至:

def httpstatus(self, url, data=None, **kwargs):
    # Don't forget to mention in documentation that all
    # extra arguments are passed to urlopen as is.
    urlopen(url, data, **kwargs)