How to compare a specific column in two csv files and output differences to a third file

Question

I have two csv files named test1.csv and test2.csv and they both have a column named 'Name'. I would like to compare each row in this Name column between both files and output the ones that don't match to a third file. I have seen some examples using pandas, but none worked for my situation. Can anyone help me get a script going for this?

Test2 will be updated to include all values from test1 plus new values not included in test1 (which are the ones i want saved to a third file)

An example of what the columns look like is:

test1.csv:

Name     Number    Status
gfd454   456       Disposed
3v4fd    521       Disposed
th678iy  678       Disposed

test2.csv

Name     Number    Status
gfd454   456       Disposed
3v4fd    521       Disposed
th678iy  678       Disposed
vb556h   665       Disposed    

Answer 1

See below.

The idea is to read the names into s python set data structure and find the new names by doing set substruction.

1.csv:

Name Number
A 12
B 34 
C 45 

2.csv

Name Number
A 12
B 34
C 45
D 77
Z 67

The code below will print {'D', 'Z'} which are the new names.

def read_file_to_set(file_name):
    with open(file_name) as f:
        return set(l.strip().split()[0] for x,l in enumerate(f.readlines()) if x > 0)



set_1 = read_file_to_set('1.csv')
set_2 = read_file_to_set('2.csv')
new_names = set_2 - set_1
print(new_names)