range(10**12)

x = (2**i for i in range(10**12))

next(x)

def infinity():
    x = 0 
    while True:
        return x
        x +=1
        
z = infinity()

z = infinity()

def infinity():
    x = 0 
    while True:
        yield x
        x +=1

z = infinity()
z

next(z)

z2 = infinity()

next(z)

next(z2)

import random
def make_random_stream(n):
    for i in range(n):
        yield random.randint(0, 100)

list(make_random_stream(10))

z = make_random_stream(100000000000000)

z

def make_reader(f):
    pass

for line in make_reader(open('spam.txt')):
    print(line)

from copy import deepcopy

a = [[1],[2],[3] ]
b = a[:]

a[0][0] = 10

a

b

b = deepcopy(a)

a[0][0] = 100

a

b