Auto deletion of messages is sometimes undesired

[algmyr]

For invocations of !pip or !d a negative result is still a useful result. Deleting the bot response and the invocation is undesired in these cases (the author still has the option to delete anyway).

[DragonSenseiGuy]

@jb3 Should we mark this as closed?

[jb3]

@jb3 Should we mark this as closed?

It's a separate issue no? I split them out intentionally because this behaviour is unrelated to the behaviour you changed in your PR.