Removing specific "part" in two brackets {} in Python

Let me explain:

               if config == "create":
                       if str(user.id) in submissions:
                           await ctx.send(embed=discord.Embed(title="ERROR", description='you already have a submission!', color=discord.Color.red()))
                           return
                       if len(submission_full) > 2 and len(submission_full) < 100:
                               submissions[str(user.id)] = {}
                               submissions[str(user.id)]["submission"] = submission_full

Basically what I have here is a discordpy submission command that creates a submission and dumps it into a json file. I am currently working on a command that does the same thing but reversed, so it deletes your submission if you want to undo.

My first thought was doing this:

                if config.lower() in ["delete","remove","undo","cancel"]:
                    await ctx.send(embed=discord.Embed(title="Removing Current Submission..", description="You will no longer have any submissions. You can create a new one at any time!", color=0xFFD700))
                    submissions[str(user.id)] = None

But it simply replaces your submission with "null".

Here is the output in the json file:

{"710826704259645450": null}

Help appreciated!

>Solution :

You want:

        del submissions[str(user.id)]