将参数传递给 requests.Session.get 会引发 TypeError

Question

我试图理解为什么在我的示例中将 params 传递给 session.get 会引发 TypeError。 response_get 返回 200 响应，而 response_open 引发 TypeError。

import requests


class Foo:

    def __init__(self):
        self.session = requests.Session()

    def get(self, url, params=None):
        """Return a Response object."""
        return requests.get(url, params)

    def open(self, url, params=None):
        """Return a Response object using the Session object."""
        return self.session.get(url, params)


if __name__ == '__main__':
    foo = Foo()
    response_get = foo.get('https://estilen.github.io')
    response_open = foo.open('https://estilen.github.io')

错误：

Traceback (most recent call last):
  File "/home/estilen/Dropbox/Python/leapy/foo.py", line 21, in <module>
    response_open = foo.open('https://estilen.github.io')
  File "/home/estilen/Dropbox/Python/leapy/foo.py", line 15, in open
    return self.session.get(url, params)
TypeError: get() takes 2 positional arguments but 3 were given

Answer 1

问题是get 需要only one un-named (positional) argument：

def get(self, url, **kwargs):
    # ...

您提供两个：url 和 params。

要解决此问题，您需要提供 params 作为命名（关键字）参数：

return self.session.get(url, params=params)