import os, sys
import numpy as np

with open('paths.txt', 'r') as paths_list:
    for file_path in paths_list:
        data = np.loadtxt(file_path.strip())
        filename = file_path[-26:-5]

        # creates the 'polyco_new.dat'-file
        os.system("tempo2 -tempo1 -polyco  "%f %f 120 15 12 @ 0" -f  ephemerides.par" %(t0, te))

        # renames the file
        os.rename('polyco_new.dat', 'polycox_'+filename+'.dat')