discord.py Set a command to only work if the user doesn't have a certain role

Question

I'm trying to set up a verification command that gives a role upon its use, but I want to set it so the user can only use the command if they don't already have the role. This is my code:

@client.command()
async def verify(ctx):
  if str(ctx.guild.id) in verify_roles:
    guild = ctx.message.author.guild
    rolegiven = ctx.message.author.guild.get_role(verify_roles.get(str(guild.id)))
    await ctx.message.author.add_roles(rolegiven)

Answer 1

One thing you could do is to retrieve rolegiven at the very beginning of your code. You can then check if the ctx.author has this role via member.roles. Here is a simplified version of the explained.

@client.command()
async def verify(ctx):
    await ctx.message.delete() # deletes the message the author sent
    if str(ctx.guild.id) in verify_roles:
        verify_role = ctx.guild.get_role(verify_roles.get(str(guild.id)))
        # check if the role is not in the author's current roles
        if verify_role not in ctx.author.roles:
            await ctx.author.add_roles(verify_role)
            await ctx.send("You have been verified!")
        else:
            await ctx.send(f"You already have {verify_role.name}")