Pandas group-by and sum

I am using this data frame:

    Fruit   Date      Name  Number
    Apples  10/6/2016 Bob    7
    Apples  10/6/2016 Bob    8
    Apples  10/6/2016 Mike   9
    Apples  10/7/2016 Steve 10
    Apples  10/7/2016 Bob    1
    Oranges 10/7/2016 Bob    2
    Oranges 10/6/2016 Tom   15
    Oranges 10/6/2016 Mike  57
    Oranges 10/6/2016 Bob   65
    Oranges 10/7/2016 Tony   1
    Grapes  10/7/2016 Bob    1
    Grapes  10/7/2016 Tom   87
    Grapes  10/7/2016 Bob   22
    Grapes  10/7/2016 Bob   12
    Grapes  10/7/2016 Tony  15

I want to aggregate this by name and then by fruit to get a total number of fruit per name.

    Bob,Apples,16 ( for example )

I tried grouping by Name and Fruit but how do I get the total number of fruit.

use the sum() method

    df.groupby(['Fruit','Name']).sum()

    Out[31]: 
                   Number
    Fruit   Name         
    Apples  Bob        16
            Mike        9
            Steve      10
    Grapes  Bob        35
            Tom        87
            Tony       15
    Oranges Bob        67
            Mike       57
            Tom        15
            Tony        1

From: stackoverflow.com/q/39922986