<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def post_gist(content, description='', filename='file', auth=False):
 """Post some text to a Gist, and return the URL."""

    post_data = json.dumps({
      "description": description,
      "public": True,
      "files": {
        filename: {
          "content": content
        }
      }
    }).encode('utf-8')

    headers = make_auth_header() if auth else {}
    response = requests.post("https://api.github.com/gists", data=post_data, headers=headers)
    response.raise_for_status()
    response_data = json.loads(response.text)
    return response_data['html_url']