Github API不接受JSON格式的Unicode字符

Question

当我从Unicode字符文件中读取并尝试通过API为发生的异常创建Github问题时发生异常：

Traceback (most recent call last):
  File "./item.py", line 320, in <module>
    auto_issue(opt.hashToCrack, e, e.message)
  File "/home/baal/bin/python/settings.py", line 480, in auto_issue
    _failure(issue, hashed_string, error)
  File "/home/baal/bin/python/github/create_issue.py", line 109, in _failure
    urllib2.urlopen(req).read()
  File "/usr/lib/python2.7/urllib2.py", line 154, in urlopen
    return opener.open(url, data, timeout)
  File "/usr/lib/python2.7/urllib2.py", line 435, in open
    response = meth(req, response)
  File "/usr/lib/python2.7/urllib2.py", line 548, in http_response
    'http', request, response, code, msg, hdrs)
  File "/usr/lib/python2.7/urllib2.py", line 473, in error
    return self._call_chain(*args)
  File "/usr/lib/python2.7/urllib2.py", line 407, in _call_chain
    result = func(*args)
  File "/usr/lib/python2.7/urllib2.py", line 556, in http_error_default
    raise HTTPError(req.get_full_url(), code, msg, hdrs, fp)
urllib2.HTTPError: HTTP Error 422: Unprocessable Entity

我做了一些研究并得出结论，当异常信息中有Unicode字符时会发生这种情况。我如何创建Github问题看起来像这样：

def _failure(issue, hashed_string, error):

    def __create_issue_ext():
        retval = []
        for _ in range(5):
            retval.append(random.choice(string.ascii_letters))
        return ''.join(retval)

    issue_title = "Unhandled Exception {}({})".format(issue, __create_issue_ext())
    issue_data = {
        "title": issue_title,
        "body": open("{}/lib/github/issue_template".format(os.getcwd())).read().format(
            type(error).__name__, (error.args, error.message), platform.platform(),
            hashed_string, sys.argv
        )
    }
    req = urllib2.Request(
        url="https://api.github.com/repos/<name>/<project>/issues", data=json.dumps(issue_data),
        headers={"Authorization": "token {}".format(__handle(__get_encoded_string()))})

    urllib2.urlopen(req).read()
    lib.settings.LOGGER.info(
        "Your issue has been created with the title '{}'.".format(
            issue_title
        )
    )

现在这样可行，只要Exception字符串中没有Unicode字符即可。所以我的问题是，有没有办法可以将Unicode转换为JSON格式，或者在将Unicode字符添加到JSON格式之前删除Unicode字符的异常字符串？