Python Pandas - check value in two columns, sum the 3rd column

Question

I have a dataset which looks similar to this (but 10000 rows instead of 6, and 100 different artists and more genres:

Year	Genre	Artist	Cost
2018	Classical	Bach	5
2019	Jazz	Beethoven	6
2019	Rock	Mozart	10
2020	Classical	Beethoven	5
2019	Rock	Beethoven	10
2020	Classical	Beethoven	3

Using Pandas I want to create a break down of the total cost, for example for Beethoven:

Genre	Total Cost
Classical	8
Jazz	6
Rock	10

I know I can have conditional summation using .loc as shown below which works in adding the total cost of classical songs

df.loc[df['Genre'] == 'Classical',Cost].sum()

So basically, Pandas docs only show examples with a single conditional like I have above and I want to be able to check both the Genre and Artist columns and sum by Genre for each Artist

sounds like you want [`groupby`](https://stackoverflow.com/questions/39922986/pandas-group-by-and-sum) — Joshua Voskamp, Nov 11 '21 at 19:20

score 1 · Answer 1 · answered Nov 11 '21 at 19:22

1

What's your expected output? Does

df.groupby(['Genre','Artist']).Cost.sum()

do what you want?

answered Nov 11 '21 at 19:22

Joshua Voskamp

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Python Pandas - check value in two columns, sum the 3rd column

1 Answers1