python slackclient userslist

Question

我正在尝试使用python slackclient。 我得到json.decoder.JSONDecodeError：期望值：第1行第1列（char 0）错误，在下面的代码中打印（slack_client.api_call（＆＃34; users.list＆＃34;））。我试过这样，但仍然得到错误，打印（json.loads（slack_client.api_call（＆＃34; users.list＆＃34;））） 请建议可能出错的地方， 前2个api调用工作正常并返回结果。只有用户列表api调用才给我错误

print (slack_client.api_call("api.test"))
print (slack_client.api_call("auth.test"))
print (slack_client.api_call("users.list"))

Traceback (most recent call last):
  File "print_bot_id.py", line 15, in <module>
    print (slack_client.api_call("users.list"))
  File "/Users/vt/anaconda3/lib/python3.6/site-packages/slackclient/_client.py", line 83, in api_call
    result = json.loads(self.server.api_call(method, timeout=timeout, **kwargs))
  File "/Users/vt/anaconda3/lib/python3.6/json/__init__.py", line 354, in loads
    return _default_decoder.decode(s)
  File "/Users/vt/anaconda3/lib/python3.6/json/decoder.py", line 339, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/Users/vt/anaconda3/lib/python3.6/json/decoder.py", line 357, in raw_decode
    raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

@smarx，curl for users.list端点什么都不返回，有不同的终点

    $ curl -X POST https://slack.com/api/api.test?token='abc'
{"ok":true,"args":{"token":"abc"}}
m-C02KL0B1FFT4:slack_bot vt$ curl -X POST https://slack.com/api/users.list?token='abc'
$