[PYTHON] Introduction to discord.py

Template

The template is the part that becomes the pattern when writing the program code.

Discord.py template

import discord
token = "" #Assign token here
client = discord.Client()

#What to do when the bot is ready
@client.event
async def on_ready():
    print("ready")

#Write other processing below from here ↓


# —-So far--


client.run(token)

Event handler

An event handler is a function that separates processing for each event that occurs on discord.

The event handler description method is as follows.

@client.event
async def event handler name(argument):
processing

Main event handlers

Note If you register the same event handler more than once, it will not work.

ex)

#Bad example
@client.event
async def on_message(message):
processing

@client.event
async def on_message(message):
processing

Event handler reference discord.py API refarence

type of discord.py

discord.py has its own types like str and int

Main types

discord.Message The information of the message is organized, Main attributes

Reference

discord.TextChannel Information on the text channel is collected Main attributes

Reference

discord.Role Information on roles is collected.

Main attributes

Reference

discord.Member Information on members is collected.

Reference

Operate discord

Each type has a method for sending messages and granting roles, as well as a Attribute. From the following, I will explain the methods and list the methods that are often used.

About await

The type of discord.TextChannel has a methodsend ()that sends a message. Also, the type of discord.Guild has a methodget_channel (channel ID)to get the channel.

I will summarize the outline of each method for the time being

@client.event
async def on_message(message):
    send_message = "I received a message." #Message content
    guild = message.guild #The server to which the message was sent
    channel = guild.get_channel(00000000000) #Get channel
    await send_channel.send(send_message)#Send message

The send () method used on line 6 has a await. On the other hand, the get_channel method used in line 5 does not have await.

From here, I will explain about this await, If it's difficult, there may be some misunderstandings, but operate it in a visible way on discord. ex (send message, add reaction, create channel

Imagine that things need await.

On the contrary, getting a channel, checking if the user is a friend, etc. Interpret that await is not attached to the method that performs processing such as acquiring information.

Explanation of await

await is prefixed when the function to be executed is a coroutine This is called the async/await syntax.

Functions with async are called coroutine functions,

What is a coroutine function?

Normal functions are executed as synchronous processing. In other words, if function B is executed while function A is being executed, the processing of function A will be interrupted and the processing of function B will start. As soon as function B finishes, processing of function A resumes.

However, the coroutine function is executed as an asynchronous process, You can run a task in parallel with another process.

import time

def wait_A():
    print("Start process A")
    time.sleep(1)
    print("End process A")

def wait_B():
    print("Start process B")
    time.sleep(2)
    print("End process B")

def wait_C():
    print("Start process C")
    time.sleep(3)
    print("End process C")

if __name__ == "__main__":
    wait_A()
    wait_B()
    wait_C()

Run this program.

~output~
Start process A
End process A
Start process B
End process B
Start process C
End process C

It will be.

Define this as a coroutine function

import asyncio
async def wait_A():
    print("Start process A")
    asyncio.sleep(3)
    print("End process A")

async def wait_B():
    print("Start process B")
    asyncio.sleep(2)
    print("End process B")

async def wait_C():
    print("Start process C")
    asyncio.sleep(1)
    print("End process C")

if __name__ == "__main__":
    await wait_A()
    await wait_B()
    await wait_C()

output
Start process A
Start process B
Start process C
End process C
End process B
End process A

It will be.

You can see that we are running multiple processes in parallel.

In other words, in the discord.py module You need to add await if the method of type was defined as a coroutine function.

You need to check the discord.py documentation to see if the type method is defined as a coroutine function or not.

There is a Method item at the beginning of each type description. Those with async at the beginning of the list are coroutine function methods.

Send various messages

Embedded message

@client.event
async def on_message(message):
    if message.content == "/embedded":
        send_embed = discord.Embed(title="Embedded title",description="Embedding description",colour=discord.Colour.red())
        send_embed.add_field(name="Field name",value="Field description")
        await message.channel.send(embed=embed)

discord.Embed is a data class for discord.py. You can instantiate the data class on line 4 and specify the title, description, and color. add_field is a method of the Embed data class, not a coroutine function. In addition to the name and value arguments, add_field has an argument called inline, which can have a bool value. The default value for inline is True Display side by side with other fields. When inline = False is set Display the field vertically.

Send the image.

await message.channel.send(File=discord.File("sample.png "))

File can be specified as the argument of send, The File argument specifies the data class of discord.File. When instantiating the File argument, you can send the image directly by specifying the file path as a string type.

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