some basic processing protocols for flask I flavored in my projects

flask_base_msg_processing.py

import os, sys
from flask import jsonify
import datetime

def convert_datatype(val):
    if type(val) == dict:
        converted = {}
        for k in val:
            if type(k) != unicode and type(k) != str:
                raise TypeError('the key of dict must be strings.')
            converted[k] = convert_datatype(val[k])
        return converted
    elif type(val) == list or type(val) == set:
        converted = []
        for v in val:
            converted.append(convert_datatype(v))
        return converted
    elif type(val) == datetime.datetime or type(val) == datetime.date:
        return datetime_to_str(val)
    else:
        return val

def send_success(data=None):
    ''' send success data to front end. 
    the key of data must be type `string`'''
    return jsonify({
        'success': True,
        'data': convert_datatype(data)})

def send_error(msg=""):
    return jsonify({
        'success': False,
        'msg': msg or "request failed on the server!"
        })

def str_to_datetime(string):
    return datetime.datetime.strptime(string, "%Y-%m-%d %H:%M:%S")

def datetime_to_str(date):
    return datetime.datetime.strftime(date, "%Y-%m-%d %H:%M:%S")