Turn sales into long format with columns region, month, revenue. Store it in result.
import pandas as pd
sales = pd.DataFrame({
"region": ["North", "South", "West"],
"Jan": [420, 380, 500],
"Feb": [455, 390, 480],
"Mar": [430, 410, 470],
})Store your final answer in a variable named result.
Run your code to see the output here.