[Solved] Reading every nth line into a column from txt file

[Laplace12]

Hey!

I have a text file that I want to sort out. I've coded this and tried dataframe, but that only prints the last line. The code I have now is this, producing the txt file:

with open(output) as file, open(out, 'w') as file_out:
    for line in file:
        if '2101' in line and found:
            a = line.split()
            print(a[1], file=file_out)
        elif 'Lifetimes' in line and found:
            b = line.split()
            print(b[3], b[4], b[5], file=file_out)
        elif 'Std deviations' in line and found:
#            print(c[3:6])
            c = line
            print(deviations(c), file=file_out)
        elif 'Intensities' in line and found:
            d = line.split()
            print(d[3], d[4], d[5], file=file_out)
        elif 'Time-zero' in line and found:
            e = line.split()
            print(e[4], file=file_out)
        else:
            found = True

#This is what I tried so far
with open(out) as a:
    cpt = 0
    for line in a:
        cpt += 1
        if cpt == 8:
            print(line)
            cpt = 0

The 'out' file is like this:

Number
Value1
Deviation
Value2
Deviation
Value3
Deviation
Number
Value1
Deviation
...

So basically the file is now a list I want to sort so that Lifetimes are all in one column, Value1 in the next, then Deviation, Value2, its deviation so on; I want every 8th value in the same column, and I'm guessing this could somehow be done by creating a loop that prints, skips 7 values and prints the next so that the start number could be changed from 1-7. I need to save the results in another file, so perhaps it'd be easier to code the columns in the 'out' file already without creating so many files, but for now it's enough to get the data sorted properly, so even the simplest code to produce columns from the txt file works!