| Step | Action | Result | |------|--------|--------| | | Build a tiny DataFrame (or read a CSV) | df with the six raw columns | | 2️⃣ Create event_id | Concatenate the textual columns with hyphens, lower‑casing for consistency | "kansai-enkou-45-chiharu-2021" | | 3️⃣ Create same_year | Compare year_1 and year_2 ; 1 = match, 0 = mismatch | Helps you quickly spot rows where the two year entries differ | | 4️⃣ (Optional) duration_years | abs(year_2 - year_1) if you need a numeric span | Not activated in the final version, but shown as a comment |