Doing calculation with ascii file

[Mike]

Hello!
I have file named DATA.TXT which contains:

Output:
colA,colB
324,234
346,341
147,346
234,567
368,405
344,643
235,235
236,567

I am trying to read this in using line-by-line (for learning purpose), then add new column with sum on first two number. So that when I save the new file, I get:

Output:
colA,colB,Sum
324,234,558
346,341,687
147,346,493
234,567,801
368,405,773
344,643,987
235,235,470
236,567,803

And so far I am using this code:

f = open('DATA.TXT', 'r')
next(f)
for line in f:
 print(line),
f.close()

[snippsat]

To take a little further,and is better to use with open() then don't need to use close() as it dos automatically.

with open('col.txt') as f:
    next(f)
    for line in f:
        line = line.strip()
        num1, num2 = line.split(',')
        num1, num2 = int(num1), int(num2)

So now is ready to continue further,if i do a test after running this code.

>>> num1 + num2
803

As expected i get the last calculation.

[Mike]

Thank you! Tried Your solution and it works.
Added lines:

num3 = num1 + num2
print(num1,num2,num3)

Which gives the first row:

Output:
324,234,803

Now somehow have to append (?) it and use FOR cycle to loop every row or do "next i" like in Excel VBA.

[Mike]

I guess I solved my problem.
Here is the script:

with open('file.txt',"r") as in_file, open('file2.txt',"w") as out_file:
	next(in_file)
	for line in in_file:
		line = line.strip()
		num1, num2 = line.split(',')
		num1, num2 = int(num1), int(num2)
		num3 = num1 + num2
		out_file.write(str(num1) + "," + str(num2) + "," + str(num3) + "\n")
		continue

Which outputs external file "file2.txt", although without headers that I removed using command "next(in_file)"

Output:
324,234,558
346,341,687
147,346,493
234,567,801
368,405,773
344,643,987
235,235,470
236,567,803

[snippsat]

Yes can do it like this.
Here an other version you can look at using f-string.
Also put in header line just as a example.
See that with string formatting(f-string) it look better no need for str() or +.

with open('col.txt') as f,open('total.txt', 'w') as f_out:
    header = next(f)
    c1, c2 = header.strip().split(',')
    f_out.write(f'{c1} {c2}  Sum\n')
    for line in f:
        line = line.strip()
        num1, num2 = line.split(',')
        num1, num2 = int(num1), int(num2)
        num3 = num1 + num2
        f_out.write(f'{num1} + {num2}  ${num3}\n')

Output:
colA colB  Sum
324 + 234  $558
346 + 341  $687
147 + 346  $493
234 + 567  $801
368 + 405  $773
344 + 643  $987
235 + 235  $470
236 + 567  $803

[Mike]

Thanks! Although a bit confusing is the header separating-adding thing.