funcschema.py

import sys
import re
import inspect


def get_func_schema(function: callable) -> dict:
    """
    Return the data schema of a function.
    {
        "function": function,
        "description": "function description",
        "parameters": {
            "type": "object",
            "properties": {
                "parameter_a": {
                    "type": "str",
                    "description": "parameter_a description"
                },
                "parameter_b": {
                    "type": "int",
                    "description": "parameter_b description"
                },
                "parameter_c": {
                    "type": "str",
                    "description": "parameter_c description",
                    "enum": ["a", "b", "c"]
                },
            },
            "required": ["parameter_a", "parameter_b"]
        }
    }
    """
    func_doc = function.__doc__
    # Google Style Docstring
    if func_doc is None:
        raise Exception("Function {} has no docstring.".format(function.__name__))
    func_doc = func_doc.strip().replace('    ','').replace('\t', '')
    # extract doc of args from docstring
    doc_spt = func_doc.split('\n\n')
    desc = doc_spt[0]
    args = doc_spt[1] if len(doc_spt) > 1 else ""
    returns = doc_spt[2] if len(doc_spt) > 2 else ""

    # extract args
    # delete the first line of args
    arg_lines = args.split('\n')[1:]
    arg_doc_list = re.findall(r'(\w+)(\((\w+)\))?:\s*(.*)', args)
    args_doc = {}
    for arg_line in arg_lines:
        doc_tuple = re.findall(r'(\w+)(\(([\w\[\]]+)\))?:\s*(.*)', arg_line)
        if len(doc_tuple) == 0:
            continue
        args_doc[doc_tuple[0][0]] = doc_tuple[0][3]

    # extract returns
    return_doc_list = re.findall(r'(\w+):\s*(.*)', returns)

    params = enumerate(inspect.signature(function).parameters.values())
    parameters = {
        "type": "object",
        "required": [],
        "properties": {},
    }


    for i, param in params:

        # 排除 self, query
        if param.name in ['self', 'query']:
            continue

        param_type = param.annotation.__name__

        type_name_mapping = {
            "str": "string",
            "int": "integer",
            "float": "number",
            "bool": "boolean",
            "list": "array",
            "dict": "object",
        }

        if param_type in type_name_mapping:
            param_type = type_name_mapping[param_type]

        parameters['properties'][param.name] = {
            "type": param_type,
            "description": args_doc[param.name],
        }

        # add schema for array
        if param_type == "array":
            # extract type of array, the int of list[int]
            # use re
            array_type_tuple = re.findall(r'list\[(\w+)\]', str(param.annotation))

            array_type = 'string'

            if len(array_type_tuple) > 0:
                array_type = array_type_tuple[0]

            if array_type in type_name_mapping:
                array_type = type_name_mapping[array_type]

            parameters['properties'][param.name]["items"] = {
                "type": array_type,
            }

        if param.default is inspect.Parameter.empty:
            parameters["required"].append(param.name)

    return {
        "function": function,
        "description": desc,
        "parameters": parameters,
    }