z1.py

import itertools
#itertools.count() used in zip()
l1=[5,15,25]
l2=zip(itertools.count(),l1)
#It will return zip object which is an iterable instance of zip class
print (l2)#Output:<zip object at 0x032C92C8>


#we can convert zip object to list.
print (list(l2))#Output:[(0, 5), (1, 15), (2, 25)]


# We can access the zip object by using "for loop".This is more efficient way to access large sequences.It won't be memory intensive.
l3=zip(itertools.count(),l1)
for i in l3:
    print (i)
'''
Output:
(0, 5)
(1, 15)
(2, 25)
'''