[FIXED] Adding data to a column and append it

Issue

I have a input data in a file input.txt. I want to add 200 with each row of 4th column and want to append just beside to it in the format same as original.

Input.txt

>   >   >
0.000   5.064   -0.15835E-01 -7.755619582136471027e-03
0.700   9.064   -0.21715E-02 -1.302134466433525067e-02
0.800   5.064   0.18954E-01 -1.691809184964498253e-02
>   >   >
0.500   4.977   0.32899E-02 1.439701445411046415e-02
0.200   6.977   0.15972E-01 6.094966468334198084e-03
0.700   4.977   0.30631E-01 -5.640445453166963163e-03

out.txt

>   >   >
0.000   5.064   -0.15835E-01 -7.755619582136471027e-03 199.99224438041787
0.700   9.064   -0.21715E-02 -1.302134466433525067e-02 199.98697865533566
0.800   5.064   0.18954E-01 -1.691809184964498253e-02  199.98308190815035
>   >   >
0.500   4.977   0.32899E-02 1.439701445411046415e-02   200.01439701445412
0.200   6.977   0.15972E-01 6.094966468334198084e-03   200.00609496646834
0.700   4.977   0.30631E-01 -5.640445453166963163e-03  199.99435955454683

I tried :

import numpy as np
data=np.loadtxt('input.txt')
data1=data(:,3)+200

I am getting error ValueError: could not convert string to float: '>' I hope some expert will help me overcoming this problem.

Solution

You have non-numeric symbols in the file. You can treat them as comments:

data = np.loadtxt('input.txt', comments=">")

But then you will not be able to preserve them in the output file. I am afraid your only option is to read the file line by line in a loop:

CHANGE = 200
with open('input.txt') as infile, open('out.txt', 'w') as outfile:
    for line in infile:
        if not line.startswith('>'): # Needs a modification
            parts = line.split()
            parts.append(str(float(parts[3]) + CHANGE) + '\n')
            line = ' '.join(parts)
        outfile.write(line)

Answered By - DYZ