Merging repeating data cells in csv
Pandas is a python library that you will find very useful for these types of tasks.

Here is a stack overflow post that tells you how to do what you want to accomplish.

It boils down to three very pythonic lines with a groupby and transformation followed by a drop_duplicates:

import pandas
df = pandas.read_csv('csvfile.csv', header = 0)
df['Total'] = df.groupby(['Name', 'Age'])['Salary'].transform('sum')
df.drop_duplicates(take_last=True)