In [1]:

    

n = 10**7
filename = 'bigdata'


    

In [2]:

    

import random


    

In [3]:

    

with open(filename, 'w') as f:
    for _ in range(n):
        print(random.randint(1, n), file=f)


    

In [4]:

    

def foo(filename):
    return [int(line.strip()) for line in open(filename)]


    

In [5]:

    

%timeit foo(filename)


    

    




1 loop, best of 3: 6.46 s per loop

In [6]:

    

a = foo(filename)
len(a), a[:3], a[-3:]


    

    
Out[6]:





(10000000, [2937736, 8865497, 9244595], [6419711, 7310417, 7464754])