change information every 14 rows python

Question

I'm currently trying to get the first date in every 14 rows and replace it on the following dates. Ex: I have these data in a txt file

02/dez  06:03   18.45   0.16    18.45   0.04
02/dez  06:03   17.56   0.26    17.62   0.21
02/dez  06:03   16.43   0.39    16.65   0.34
02/dez  06:03   12.72   0.39    14.35   0.38
02/dez  06:03   4.70    0.49    5.29    0.49
02/dez  06:03   3.87    0.41    4.41    0.41
02/dez  06:03   3.53    0.36    4.04    0.33
02/dez  06:04   2.62    0.55    3.05    0.54
02/dez  06:04   1.69    0.44    1.96    0.46
02/dez  06:04   1.59    0.34    1.85    0.35
02/dez  06:04   1.56    0.31    1.80    0.29
02/dez  06:04   0.54    0.51    0.64    0.50
02/dez  06:04   0.47    0.43    0.56    0.45
02/dez  06:04   0.00    0.48    0.00    0.50
02/dez  06:19   18.87   0.12    18.78   0.04
02/dez  06:19   18.32   0.23    18.18   0.23
02/dez  06:19   17.75   0.47    17.57   0.36
02/dez  06:19   16.63   0.51    16.31   0.41
02/dez  06:19   7.07    0.77    6.77    0.64
02/dez  06:19   5.86    0.65    5.56    0.55
02/dez  06:19   5.44    0.59    5.04    0.46
02/dez  06:20   4.32    0.78    3.80    0.66
02/dez  06:20   2.91    0.72    2.41    0.55
02/dez  06:20   2.85    0.67    2.24    0.47
02/dez  06:20   2.85    0.68    2.16    0.39
02/dez  06:20   0.98    0.85    0.76    0.60
02/dez  06:20   0.74    0.72    0.65    0.53
02/dez  06:20   0.00    0.73    0.00    0.60
02/dez  06:34   18.91   0.10    18.88   0.03
02/dez  06:34   18.44   0.29    18.39   0.20
02/dez  06:34   17.95   0.41    17.91   0.35
02/dez  06:34   17.07   0.51    17.09   0.47
02/dez  06:34   7.79    0.82    8.17    0.78
02/dez  06:34   6.40    0.73    6.86    0.71
02/dez  06:35   5.89    0.67    6.36    0.61
02/dez  06:35   4.49    0.83    4.92    0.86
02/dez  06:35   2.88    0.74    3.20    0.75
02/dez  06:35   2.69    0.66    3.04    0.70
02/dez  06:35   2.62    0.58    2.99    0.63
02/dez  06:35   0.94    0.82    1.10    0.88
02/dez  06:35   0.80    0.75    0.94    0.82
02/dez  06:35   0.00    0.85    0.00    0.89
                   .
                   .
                   .

What I'm trying to achieve is:

02/dez;06:03;18.45;0.16;18.45;0.04
02/dez;06:03;17.56;0.26;17.62;0.21
02/dez;06:03;16.43;0.39;16.65;0.34
02/dez;06:03;12.72;0.39;14.35;0.38
02/dez;06:03;4.70;0.49;5.29;0.49
02/dez;06:03;3.87;0.41;4.41;0.41
02/dez;06:03;3.53;0.36;4.04;0.33
02/dez;06:03;2.62;0.55;3.05;0.54
02/dez;06:03;1.69;0.44;1.96;0.46
02/dez;06:03;1.59;0.34;1.85;0.35
02/dez;06:03;1.56;0.31;1.80;0.29
02/dez;06:03;0.54;0.51;0.64;0.50
02/dez;06:03;0.47;0.43;0.56;0.45
02/dez;06:03;0.00;0.48;0.00;0.50
02/dez;06:19;18.87;0.12;18.78;0.04
02/dez;06:19;18.32;0.23;18.18;0.23
02/dez;06:19;17.75;0.47;17.57;0.36
02/dez;06:19;16.63;0.51;16.31;0.41
02/dez;06:19;7.07;0.77;6.77;0.64
02/dez;06:19;5.86;0.65;5.56;0.55
02/dez;06:19;5.44;0.59;5.04;0.46
02/dez;06:19;4.32;0.78;3.80;0.66
02/dez;06:19;2.91;0.72;2.41;0.55
02/dez;06:19;2.85;0.67;2.24;0.47
02/dez;06:19;2.85;0.68;2.16;0.39
02/dez;06:19;0.98;0.85;0.76;0.60
02/dez;06:19;0.74;0.72;0.65;0.53
02/dez;06:19;0.00;0.73;0.00;0.60
02/dez;06:34;18.91;0.10;18.88;0.03
02/dez;06:34;18.44;0.29;18.39;0.20
02/dez;06:34;17.95;0.41;17.91;0.35
02/dez;06:34;17.07;0.51;17.09;0.47
02/dez;06:34;7.79;0.82;8.17;0.78
02/dez;06:34;6.40;0.73;6.86;0.71
02/dez;06:34;5.89;0.67;6.36;0.61
02/dez;06:34;4.49;0.83;4.92;0.86
02/dez;06:34;2.88;0.74;3.20;0.75
02/dez;06:34;2.69;0.66;3.04;0.70
02/dez;06:34;2.62;0.58;2.99;0.63
02/dez;06:34;0.94;0.82;1.10;0.88
02/dez;06:34;0.80;0.75;0.94;0.82
02/dez;06:34;0.00;0.85;0.00;0.89
02/dez;06:50;19.81;0.12;19.36;0.04
02/dez;06:50;19.57;0.27;19.06;0.21
02/dez;06:50;19.37;0.48;18.79;0.40
02/dez;06:50;18.94;0.59;18.42;0.49
02/dez;06:50;15.15;1.53;13.23;1.26
02/dez;06:50;10.78;1.23;11.06;1.19
02/dez;06:50;9.13;1.06;10.11;1.10
02/dez;06:50;6.99;1.23;7.79;1.31
02/dez;06:50;4.54;1.21;4.97;1.22
02/dez;06:50;4.27;1.11;4.63;1.12
02/dez;06:50;4.15;1.04;4.45;1.08
02/dez;06:50;1.51;1.30;1.61;1.29
02/dez;06:50;1.29;1.25;1.34;1.19
02/dez;06:50;0.00;1.35;0.00;1.31
            .
            .
            .

My code works fine for 14 rows in a file, but I'm stuck in getting the date in the lines 14, 28,42, 56 and replacing it on the following 13 rows. Here is my code:

result = []
with open('test.txt') as f:
    lines = f.readlines()
    firstLines = lines[0].strip().split('   ')
    hour = firstLines[1]
    for line in lines:
        col = line.strip().split('  ')
        if col[1] != hour:
            col[1] = hour
        result.append(col)
    outfile = open('result.txt', 'w')
    for i in result:
        outfile.write(';'.join(i) + "\n")

I tried something with:

with open(filename) as f:
    lines = f.readlines()
    for i in range(0, len(lines), 14):
        firstLines = lines[0].strip().split('   ')
        hour = firstLines[1]
        #col = lines[i:i + 14] I got stuck here

Can someone help me?

Answer 1

Are you familiar with the modulo (%) operator? Using it would let you know when you've started a new row. So, something like:

for line_number, line in enumerate(lines):
   if (line_number % 14) == 0:
        # Every 14th row, save the value of column 1 as curHour
        curHour = col[1]
    # Use the value of curHour which changes every 14th row
    result[1] = curHour
    ...

Answer 2

You have one for-loop that runs in steps of 14, so far so good. Then just add a second for loop inside of the first one that runs from 0 to 13 and copies the value into the field.

You'll have to add a bit of extra code in case the number of lines isn't a multiple of 14 (say you have 32 lines, then you have 2 complete sets of 14s and one set of just 4).

Alternatively, you could look into the pandas package which is much nicer for reading such data files and manipulating them, but explaining it here would be a bit outside the scope. Just give it a quick look.

Answer 3

Possibly something like this may work with some tweaking.

with open(filename) as f:
    lines = f.readlines()
    for i in range(0, len(lines), 14):
        firstLines = lines[0].strip().split('   ')
        hour = firstLines[1]
        for j in range(i, i+14):
            line = lines[j]
            line.strip().split('   ')[0] = hour