Why my Discord bot always sends duplicated message?

Question

As the title says, when my Discord bot tries to send messages, it always sends the message twice!
I know where the problem is in the code, but I don't know how to fix it.

Code about sending messages:

    for i in range(len(final_msg_list)):
        new_log = str(message.channel) + "/" + str(client.user) + ":\n" + str(final_msg_list[i-1]) + "\n\n"
        log_writter.write_log(new_log)
        if isinstance(final_msg_list[i], discord.File):
            await message.channel.send(file=final_msg_list[i])
        elif isinstance(final_msg_list[i], discord.Embed):
            await message.channel.send(embed=final_msg_list[i])
        elif isinstance(final_msg_list[i], str):
            await message.channel.send(final_msg_list[i])

The bot's log:

[2022-04-15 PM 12:11:42]Channel/me#5877:
y!test

[2022-04-15 PM 12:11:42]Channel/Bot#0359:
test

[2022-04-15 PM 12:11:42]Channel/Bot#0359:
test

And sorry for my bad English...

UPDATE: I found a way to solve that problem!

    for i in range(len(final_msg_list)):
        current_msg = final_msg_list[i]
        if isinstance(current_msg, discord.File):
            await message.channel.send(file=final_msg_list[i])
        elif isinstance(current_msg, discord.Embed):
            await message.channel.send(embed=final_msg_list[i])
        elif isinstance(current_msg, str):
            await message.channel.send(final_msg_list[i])

I set a new variable: current_msg = final_msg_list[i], and change every final_msg_list[i] into current_msg, and that works!
But I still don't know how this work...?