Change specific column values from a text file using Python

Question

I have a text file as following:

1  1  2  1  1e8
2  1  2  3  1e5
3  2  3  2  2000
4  2  5  6  1000
5  2  4  3  1e4
6  3  6  4  5000
7  3  5  2  2000
8  3  2  3  5000
9  3  4  5  1e9
10 3  2  3  1e6

My question is that how can I change one column(for example divide all the data from the last column to 900) and save the whole data in a new file? Thanks in advance

Answer 1

You can use numpy library. The code below should do it.

import numpy as np

# assume the data is in.txt file
dat = np.loadtxt('in.txt')

# -1 means the last column
dat[:, -1] = dat[:, -1]/900

# write the result to the out.txt file
# fmt is the format while writing to the file
# %.2f means that it will save it to the 2 digits precision
np.savetxt('out.txt', dat, fmt='%.2f')