why use an iterator in python code example

Example: python how to use iter

s = 'hello'
s_iter = iter(s) #Changes the string to an iterator
print(next(s_iter)) #Will print h
print(next(s_iter)) #Will print e
print(next(s_iter)) #Will print l
print(next(s_iter)) #Will print l
print(next(s_iter)) #will print o