1>>> from numpy import *
2>>>
3>>> data = loadtxt("myfile.txt") # myfile.txt contains 4 columns of numbers
4>>> t,z = data[:,0], data[:,3] # data is 2D numpy array
5>>>
6>>> t,x,y,z = loadtxt("myfile.txt", unpack=True) # to unpack all columns
7>>> t,z = loadtxt("myfile.txt", usecols = (0,3), unpack=True) # to select just a few columns
8>>> data = loadtxt("myfile.txt", skiprows = 7) # to skip 7 rows from top of file
9>>> data = loadtxt("myfile.txt", comments = '!') # use '!' as comment char instead of '#'
10>>> data = loadtxt("myfile.txt", delimiter=';') # use ';' as column separator instead of whitespace
11>>> data = loadtxt("myfile.txt", dtype = int) # file contains integers instead of floats