47.Iterators

#next() and iter() are built-in functions used for working with iterators and iterable objects.
#The next() function is used to retrieve the next item from an iterator.
#The iter() function is used to create an iterator object from an iterable. It takes an iterable (such as a list, tuple, string, etc.) as an argument and returns an iterator object.

#Example for next():

def generate():
    for i in range(5):
        yield i

g = generate()
print(next(g))  #Output: 0
print(next(g))  #Output: 1
print(next(g))  #Output: 2
print(next(g))  #Output: 3
print(next(g))  #Output: 4
#print(next(g))  #Output: Error [After yielding all the values next() caused a StopIteration error]

#Example for iter():

s = "Hola!"

#next(s) #Gives error
#A string object supports iteration, but can't directly iterate over it as we could with a generator function. The iter() function allows us to do just that!

si = iter(s)
for i in range(len(s)):
  print(next(si))
 
"""
Output:
H
o
l
a
!
"""