python pandas dataframe add same row values

Question

I have a dataframe which looks like this:

Fruit        Quantity
orange       4
grape        2
apple        3
grape        2
orange       1

I want to sum up the quantity column based off of the same item name in the fruit column. The desired result is :

Fruit      Quantity 
orange     5
apple      3
grape      4

tlentali · Accepted Answer · 2021-11-02 12:44:15Z

3

The answers from @GevorgAtanesyan and @d.b work perfectly.
However to get a DataFrame instead of a Serie as output, this notation can be used :

>>> df.groupby('Fruit')['Quantity'].sum().reset_index()
    Fruit   Quantity
0   apple   3
1   grape   4
2   orange  5

EDIT :
As suggested by @EmiOB, it is even tidier to write it like this :

>>> df.groupby('Fruit', as_index=False)['Quantity'].sum()
    Fruit   Quantity
0   apple   3
1   grape   4
2   orange  5

answered Nov 1, 2021 at 23:11

tlentali

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1 Comment

or add as_index=False in the df.groupby bit, like so: df.groupby('Fruit', as_index=False).sum() Personally, I think it's a bit tidier

Gevorg Atanesyan · Accepted Answer · 2021-11-01 22:49:40Z

2

Value counts is the best way

df.groupby('Fruit').sum()

answered Nov 1, 2021 at 22:41

Gevorg Atanesyan

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