JSON错误：json.decoder.JSONDecodeError：期望值：第1行第1列（char 0）

Question

我在discord.py（python 3.6.8）中为我的discord bot制作了一个练级系统，但我一直收到这个错误，我无法理解它的含义。

这是我的代码：

import random, asyncio, os, discord, json, time
from discord.ext.commands import Bot

BOT_PREFIX = ("&")
client = Bot(command_prefix=BOT_PREFIX)
client.remove_command('help')

if not os.path.exists('users.json'):
    open('users.json', 'w').close()

@client.event
async def on_message(message):
    with open("users.json", "r") as f:
        users = json.load(f)

        if message.author.bot:
            return
        if message.channel.is_private:
            return
        else:
            await update_data(users, message.author, message.server)
            number = random.randint(5,10)
            await add_experience(users, message.author, number, message.server)
            await level_up(users, message.author, message.channel, message.server)

        with open("users.json", "w") as f:
            json.dump(users, f)
    await client.process_commands(message)

async def update_data(users, user, server):
    if not user.id + "-" + server.id in users:
        users[user.id + "-" + server.id] = {}
        users[user.id + "-" + server.id]["experience"] = 0
        users[user.id + "-" + server.id]["level"] = 0
        users[user.id + "-" + server.id]["last_message"] = 0

async def add_experience(users, user, exp, server):
    if time.time() - users[user.id + "-" + server.id]["last_message"] > 5:
        users[user.id + "-" + server.id]["experience"] += exp
        users[user.id + "-" + server.id]["last_message"] = time.time()
    else:
        return

async def level_up(users, user, channel, server):
    experience = users[user.id + "-" + server.id]["experience"]
    lvl_start = users[user.id + "-" + server.id]["level"]
    lvl_end = int(experience ** (1/4))

    if lvl_start < lvl_end:
        await client.send_message(channel, f"{user.mention}, has leveled up to level {lvl_end}!")
        users[user.id + "-" + server.id]["level"] = lvl_end


print('[BOT SUCCESSFULLY STARTED]\n\n')
client.run('YOUR_TOKEN_HERE')

这是我的错误：

Ignoring exception in on_message
Traceback (most recent call last):
  File "C:\Users\NeverEndingCycle\AppData\Local\Programs\Python\Python36\lib\site-packages\discord\client.py", line 307, in _run_event
    yield from getattr(self, event)(*args, **kwargs)
  File "C:\Users\NeverEndingCycle\Desktop\Coding_Stuff\Py_Code\Bot_Testing\Logic_Tests\XP-Logic\main.py", line 14, in on_message
    users = json.load(f)
  File "C:\Users\NeverEndingCycle\AppData\Local\Programs\Python\Python36\lib\json\__init__.py", line 299, in load
    parse_constant=parse_constant, object_pairs_hook=object_pairs_hook, **kw)
  File "C:\Users\NeverEndingCycle\AppData\Local\Programs\Python\Python36\lib\json\__init__.py", line 354, in loads
    return _default_decoder.decode(s)
  File "C:\Users\NeverEndingCycle\AppData\Local\Programs\Python\Python36\lib\json\decoder.py", line 339, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "C:\Users\NeverEndingCycle\AppData\Local\Programs\Python\Python36\lib\json\decoder.py", line 357, in raw_decode
    raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

编辑：已解决此问题，如果您遇到同样的问题，请查看下面的答案。

Answer 1

该错误是因为您尝试加载的不是json而且未正确处理。

你可以知道这一点，因为json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)第1行第1列char 0表示根本没有读取json。当错误引用回第一个位置字符时，意味着该内容的格式对于要读取的json不正确。

Answer 2

好吧我明白了。我需要一次取消缩进此块：

with open("users.json", "w") as f: 
    json.dump(users, f)

这就是数据未被保存的原因。至于错误，我相信@GiraffeMan91是对的。因为没有保存数据并且JSON为空，所以没有任何东西需要解码，因此给出了JSONDecodeErorr。

以下是上述代码的工作版本：

import random, asyncio, os, discord, json, time
from discord.ext.commands import Bot

BOT_PREFIX = ("&")
client = Bot(command_prefix=BOT_PREFIX)
client.remove_command('help')

if not os.path.exists('users.json'):
    open('users.json', 'w').close()

@client.event
async def on_message(message):
    with open("users.json", "r") as f:
        users = json.load(f)

        if message.author.bot:
            return
        if message.channel.is_private:
            return
        else:
            await update_data(users, message.author, message.server)
            number = random.randint(5,10)
            await add_experience(users, message.author, number, message.server)
            await level_up(users, message.author, message.channel, message.server)

    with open("users.json", "w") as f:
        json.dump(users, f)
    await client.process_commands(message)

async def update_data(users, user, server):
    if not user.id + "-" + server.id in users:
        users[user.id + "-" + server.id] = {}
        users[user.id + "-" + server.id]["experience"] = 0
        users[user.id + "-" + server.id]["level"] = 0
        users[user.id + "-" + server.id]["last_message"] = 0

async def add_experience(users, user, exp, server):
    if time.time() - users[user.id + "-" + server.id]["last_message"] > 5:
        users[user.id + "-" + server.id]["experience"] += exp
        users[user.id + "-" + server.id]["last_message"] = time.time()
    else:
        return

async def level_up(users, user, channel, server):
    experience = users[user.id + "-" + server.id]["experience"]
    lvl_start = users[user.id + "-" + server.id]["level"]
    lvl_end = int(experience ** (1/4))

    if lvl_start < lvl_end:
        await client.send_message(channel, f"{user.mention}, has leveled up to level {lvl_end}!")
        users[user.id + "-" + server.id]["level"] = lvl_end


print('[BOT SUCCESSFULLY STARTED]\n\n')
client.run('YOUR_TOKEN_HERE')