python - TypeError: list indices must be integers, not tuple -

my code:`

#!/usr/bin/python  open("a.dat", "r") ins:     array = []     line in ins:         l=line.strip()         array.append(l)  a1 = array[:,1] print a1 

i want read a.dat array take first column.what wrong?

for loading numerical data, it's useful use numpy instead of python.

import numpy np arr = np.loadtxt('a.dat') print arr[:,0] 

numpy python library that's suited loading , manipulating numerical data (with bonus when used correctly, it's waaaay faster using python lists). in addition, dealing tabular data mixed datatypes, recommend using pandas.

import pandas pd df = pd.load_csv('a.dat', sep=' ', names=['col1', 'col2']) print df['col1'] 

numpy can found here

pandas can found here