generate random numbers where column sums upto something

randsum.py

#!/usr/bin/env python3

import numpy as np


def main():
    ncols = 3
    nrows = 100
    arr = np.random.random((nrows, ncols))
    arr = arr / arr.sum(axis=0, keepdims=1) * 100
    print(arr.shape)
    print(arr.sum(axis=0))
    np.savetxt("rand.csv", arr, delimiter=",")


if __name__ == "__main__":
    main()