requests_test.py

import requests


class RequestsTest(requests.Session):
    def __init__(self):
        super().__init__()
        self.headers["accept"] = "application/json"
        self.params["your_api_key_here"] = "my_api_key"

    def get_with_params(self, params):
        print(self.get("https://httpbin.org/get", params=params).text)

    def get_with_params_fixed(self, params):
        if isinstance(params, list):
            for k, v in self.params.items():
                params.append((k, v))
        print(self.get("https://httpbin.org/get", params=params).text)


a = RequestsTest()
print("Send a dict of params")
a.get_with_params({"foo": 1})  # Works fine
print("Send a list of params")
a.get_with_params([("foo", 1), ("foo", 2)])  # Does not send api key
print("Send a list of params with fixed version")
a.get_with_params_fixed([("foo", 1), ("foo", 2)])