Day 4 (9 12 2019): Group By - Ajarlin/Data-Science GitHub Wiki

Often we want to perform aggregate analysis across data points that share some feature, for example:

• what was the average share of the vote across all us elections for each political party.
• what was the size of the average class in each department at Rutgers in each term?
• Which instructors taught the largest classes at Rutgers and how large were they?