Iterator VS Generator in python

 Iterator :

• Object 
• Contain iterable objects ( List, tuple , set)
• used iter() and next() function 
• iter() containing an iterable object (List tuple ,set)
• next() call next element in the iterable object
• Lazy evaluation

 Basic Syntex :

list_iterObj = iter(['Ram', 'Shyam',' Mohan']) #  Contain iterable objects ( List only)

print(list_iterObj ) # output <list_iterator object at 0x000001DA2D7A2B00>

# Therefore we use the next() function or loop 

print(next(list_iterObj )) # output Ram only 

print(next(list_iterObj )) # then output Shyam only  lazy evaluation

# loop 

for item in list_iterObj:

    print(item)

#output you can guess :) 

Generator : 

• Create iterators
• It is used function but doesn't return a Type
• used yield keyword
• lazy evaluation 
• it is a generator object
• used next() function to print the next item 

 Basic Syntex :

def number(n):

    for i in range(1, n+1):

        yield i*i     # used yield keyword it is property of the generator

# generator object 

gen_obj =  number(5) 

print(gen_obj) # output <generator object number at 0x000001B0EC1760A0> 

#we have 2 options use next() function or loop

print(next(gen_obj )) # output 1

print(next(gen_obj )) # output 4  

# use loop 

for val in gen_obj:

    print(val) # guess answer and comment