A simple example of how I do logging in an API client

api_client.py

"""
When I integrate with a 3rd party API, I write a thin wrapper around it to
normalize any eccentricities and provide a well-defined Python-level API.
"""

log = logging.getLogger("acme.api")

class AcmeAPIClient(object):
    def get_widgets(self):
        """
            GET acme.com/api/widgets
            HTTP 200 Ok
            {
                "widgets": [<widget>, <widget>],
                "ok": True,
            }
        """
        return self._request("GET", "widgets")["widgets"]

    def _request(self, method, suffix, data=None, expected_errors=None):
        expected_errors = set(expected_errors or [])
        data = data or {}
        data["api_key"] = self.api_key
        url = self.base_url + suffix
        start_time = time.time()
        exc = None
        try:
            r = self._backend.request(method, url, params=data)
            resp_text = r.text
            resp_status_code = r.status_code
        except Exception as e:
            exc = e
            resp_text = ""
            resp_status_code = -1
        duration = time.time() - start_time

        try:
            resp_obj = json.loads(resp_text)
        except Exception as e:
            resp_obj = {
                "error": {
                    "message": "error decoding response: %r" %(e, ),
                    "code": -42,
                }
            }

        error = (
            {"message": repr(exc), "code": -43} if exc else
            resp_obj["error"] if "error" in resp_obj else
            None
        )

        try:
            params_str = urllib.urlencode(data)
        except Exception as e:
            params_str = repr(data)

        error_is_expected = error and error.get("code") in expected_errors
        logger = (
            log.info if not error or error_is_expected else
            log.error
        )
        logger(
            "%s %s?%s -> %s %s%s", method, url, params_str, resp_status_code,
            resp_text[:100], error or "",
            extra=OrderedDict([
                ("method", method),
                ("url", url),
                ("params", data),
                ("duration", duration),
                ("status_code", resp_status_code),
                ("response_text", resp_text),
                ] +
                ([("error", error)] if error else []) +
                ([("error_expected", error_is_expected)] if error_is_expected else [])
            ),
        )
        if error:
            if error_is_expected:
                return {
                    "error": error,
                    "error_is_expected": error_is_expected,
                }
            raise AcmeAPIError(
                error.get("message") or "<unknown>",
                error.get("code"),
            )
        return resp_obj