Made some changes to the on_message event in main.py and added a new basic command

Author: Xia3412

projects/Discord Bot/main.py

@@ -1,29 +1,93 @@
 # build a simple discord bot
 
 import discord
+from discord.ext import commands # importing commands module from discord extensions
 import os
 import random
 
 token = "Your Token Here"
 
 bot = discord.bot(comand_prefix="!")
 
+# The list below is a list that contains all the responses the bot can randomly choose from for the "ask" command
+# Scroll down to see the "ask" command's functionality
+# It is recommended to make this list in a different .txt file or .py file and then importing it to this main.py
+# file but for the sake of simplicity, I have added this list here only in the main bot file.
+
+responses_list = ["It is certain",
+                  "It is decidedly so",
+                  "Without a doubt",
+                  "Yes, definitely",
+                  "You may rely on it",
+                  "As I see it, yes",
+                  "Most likely",
+                  "Outlook good",
+                  "Yes",
+                  "Signs point to yes",
+                  "Reply hazy try again",
+                  "Ask again later",
+                  "Better not tell you now",
+                  "Cannot predict now",
+                  "Concentrate and ask again",
+                  "Don't count on it",
+                  "My reply is no",
+                  "My sources say no",
+                  "Outlook not so good",
+                  "Very doubtful"]
+
 
 @bot.event
 async def on_ready():
     print("Bot is ready")
 
 
 @bot.event
-async def on_message(message):
+async def on_message(message: discord.Message):
     if message.author == bot.user:
         return
 
     if message.content.startswith("!hello"):
-        await message.channel.send("Hello!")
+        await message.channel.send(f"Hello {message.author.mention}!")
+        return
 
     if message.content.startswith("!random"):
         await message.channel.send(random.randint(1, 100))
 
 
+# adding a "@bot.command" decorator which creates a command for the discord bot which can be then invoked by the user
+# "aliases" parameter inside the "@bot.command" decorator makes it so that the user can use multiple names to call
+# that particular command
+
+@bot.command(aliases = ["ASK", "Ask"])
+async def ask(ctx: commands.Context, *, question: str):
+
+# Note:- If we don't put a ( * ) before the question paramter, the bot will only take the first word from the user
+# input. For example: Running the command like this:- "!ask how are you?"
+# The bot will read that command as:- "how". To avoid this, we add an asterisk( * ) before the question parameter
+# so the bot will read the command as "how are you?".
+    
+    await ctx.reply(f"{ctx.author.mention} asks: **{question}**\nMy reply: **{random.choice(responses_list)}**")
+
+# the ctx object has an attribute called "reply" which will reply to the user's message when the user uses to command
+# prefix along with the command name. And the rest of the code is self explanatory. The "\n" basically makes it so
+# that the rest of the code after that "\n" will be printed in a new line. So ultimately, running this command
+# on discord will look like this:-
+    
+    # lets say user asks the bot "how are you". So the user will send: "!ask how are you".
+    # the bot will reply with "{user's discord id mention} asks: how are you"
+    #                         "My reply: {a random response from the responses list}"  
+
+# There's one last thing to do now.. which is handling error. As we can see, the "ask" commands needs a question
+# parameter.. but what if the user just uses the command and never provide the bot with the question parameter?
+# This situation will through an error called "MissingRequiredArgument". In order to avoid this, we can locally
+# create a error handler for this "ask" command. You can also use a try and except block to catch the error.
+    
+@ask.error
+async def ask_error(ctx: commands.Context, error):
+    if isinstance(error, commands.MissingRequiredArgument):
+        await ctx.reply("You didn't provide me with a question!")
+
+# the above error handler checks specifically for the error "MissingRequiredArgument". If the command encounters with
+# this error, the bot will just reply to the user's message with the sentence pasted above in the error handler
+
 bot.run(token)