How do I create df2 directly using df as input? I can't wrap my head around it...
>>> import pandas as pd>>> data = {'Year': [1990, 1990, 1990, 2022, 2022, 2022], 'City': ['Paris', 'Berlin', 'Lisbon', 'Paris', 'Berlin', 'Lisbon'], 'Population': [2.15, 3.40, 2.54, 2.11, 3.57, 2.99]}>>> df = pd.DataFrame.from_dict(data) Year City Population0 1990 Paris 2.151 1990 Berlin 3.402 1990 Lisbon 2.543 2022 Paris 2.114 2022 Berlin 3.575 2022 Lisbon 2.99>>> data2 = {'City': ['Paris', 'Berlin', 'Lisbon'], 'Population change': [2.11 - 2.15, 3.57 - 3.40, 2.99 - 2.54]}>>> df2 = pd.DataFrame.from_dict(data2) City Population change0 Paris -0.041 Berlin 0.172 Lisbon 0.45