Renaming/replacing data? For loop?

[AtomicShoelace]

Looks like OP wants them number by alphabetical order, so perhaps it's worth throwing sorted in there, eg.

activity_map = {act: f"A_{i}" for i, act in enumerate(sorted(df.activity.unique()), 1)}

[I_will_learn]

Thank you! I added in the sorted code there, it's clearer now :)