groupby function: df.groupby(by=["b"]).sum()

Asked Dec 11 '20 at 13:59

Active Dec 11 '20 at 13:59

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https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.groupby.html

This doc gives an example of groupby function:

l = [[1, 2, 3], [1, None, 4], [2, 1, 3], [1, 2, 2]]
df = pd.DataFrame(l, columns=["a", "b", "c"])

    a   b    c
0   1   2.0  3
1   1   NaN  4
2   2   1.0  3
3   1   2.0  2

 df.groupby(by=["b"]).sum()

  output:
         a   c
    b
    1.0  2   3
    2.0  2   5

I do not understand how the output like this?

asked Dec 11 '20 at 13:59

Elizabeth Shen

3

it groups the data by the values in column B, and sum's the other numeric columns. For example, when B was 2.0, C was 3 and 2, and it's sum is 5. – sophocles Dec 11 '20 at 14:01
1

yes, thank you so much for the explanation. Magic Pandas! – Elizabeth Shen Dec 11 '20 at 14:36

groupby function: df.groupby(by=["b"]).sum()

0 Answers0