ex.py

import itertools
import math
import matplotlib.pyplot as plt
import numpy as np
import tufte
from collections import namedtuple

SNPoint = namedtuple('SNPoint', ['sn_name', 'z_cmb', 'mu_mag', 'err_mu',
                                 'sample', 'flag'])

def import_data(fname):
    with open(fname, 'r') as f:
        lines = f.readlines()
    def fmt_line(line):
        return (line[0], float(line[1]), float(line[2]), float(line[3]),
                int(line[4]), line[5])
    # Ignore comments
    return [SNPoint(*fmt_line(x.split())) for x in lines if x[0] != '#']

if __name__ == '__main__':
    print import_data('datafile.txt')[0]