python - 为什么我在这段代码中得到 "TypeError: unorderable types: str() < int()"？

Question

@commands.command(pass_context=True)
@checks.serverowner()
async def change(self, ctx, change):
    channel = self.bot.get_channel('432738903221469186')
    change = ctx.message.clean_content[8:]
    now = datetime.now()
    count = len(self.changes.items()) + 1
    self.changes[count] = {'date': now.strftime("%Y-%m-%d %H:%M:%S"), 'change': change}
    dataIO.save_json('data/local/changes.json', self.changes)
    await self.bot.send_message(channel, bold("\N{SPARKLE} This change to the server was just made:") + box(change))
    await self.bot.add_reaction(ctx.message, "\N{WHITE HEAVY CHECK MARK}")

这里是 changes.json:

{
    "1" : {
        "change" : "TEST",
        "date" : "2018-06-29 01:07:37"
    }
}

这是完整的错误:

2|cdb_laun | Traceback (most recent call last):
2|cdb_laun |   File "lib/discord/ext/commands/core.py", line 50, in wrapped
2|cdb_laun |     ret = yield from coro(*args, **kwargs)
2|cdb_laun |   File "/root/craig/cdbot/cogs/local.py", line 73, in change
2|cdb_laun |     dataIO.save_json('data/local/changes.json', self.changes)
2|cdb_laun |   File "/root/craig/cdbot/cogs/utils/dataIO.py", line 20, in save_json
2|cdb_laun |     self._save_json(tmp_file, data)
2|cdb_laun |   File "/root/craig/cdbot/cogs/utils/dataIO.py", line 50, in _save_json
2|cdb_laun |     json.dump(data, f, indent=4, sort_keys=True, separators=(",", " : "))
2|cdb_laun |   File "/usr/lib64/python3.5/json/__init__.py", line 178, in dump
2|cdb_laun |     for chunk in iterable:
2|cdb_laun |   File "/usr/lib64/python3.5/json/encoder.py", line 429, in _iterencode
2|cdb_laun |     yield from _iterencode_dict(o, _current_indent_level)
2|cdb_laun |   File "/usr/lib64/python3.5/json/encoder.py", line 352, in _iterencode_dict
2|cdb_laun |     items = sorted(dct.items(), key=lambda kv: kv[0])
2|cdb_laun | TypeError: unorderable types: str() < int()

对于模糊的标题和问题，我深表歉意，我刚刚经常处理 JSON，我不理解这里的错误。我什至没有看到比较字符串和整数的位置。

我最初的想法是它与 count = len(self.changes.items()) + 1 有关，但事实并非如此。

Answer 1

对不起，我想通了。出于某种原因，在第一次运行期间，它将 JSON key 保存为字符串。在第二次运行中，它把它保存为一个整数。 self.changes 打印为:

{'2': {'date': '2018-06-29 02:02:03', 'change': 'TEST'}, '1': {'date': '2018-06-29 01:07:37', 'change': 'TEST'}}

为了解决这个问题，我只是改变了

self.changes[count] = {'date': now.strftime("%Y-%m-%d %H:%M:%S"), 'change': change}

到

self.changes[str(count)] = {'date': now.strftime("%Y-%m-%d %H:%M:%S"), 'change': change}