pandas condense dataframe by summing according to ID
# Original dataframe df:
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
df.groupby(['Fruit','Name']).sum() # Use .groupby().sum()
#Output:
Fruit Name Number
Apples Bob 16
Mike 9
Steve 10
Grapes Bob 35
Tom 87
Tony 15
Oranges Bob 67
Mike 57
Tom 15
Tony 1