langchain/output_parsers/json.py/parse_json_markdown
def parse_json_markdown(json_string: str) -> dict:
    # Try to find JSON string within triple backticks
    match = re.search(r"```(json)?(.*?)```", json_string, re.DOTALL)

    # If no match found, assume the entire string is a JSON string
    if match is None:
        json_str = json_string
    else:
        # If match found, use the content within the backticks
        json_str = match.group(2)

    # Strip whitespace and newlines from the start and end
    json_str = json_str.strip()

    # Parse the JSON string into a Python dictionary
    parsed = json.loads(json_str)

    return parsed