Python Iterator

lst = [1,2,3,4]
dic = {'w1': 'one', 'w2': 'two', 'w3': 'three'}
str = "string"
val = 8
for i in lst: print(i, end=' ') # 1 2 3 4
for i in dic: print(i, end=' ') # w1 w2 w3
for i in str: print(i, end=' ') # s t r i n g
for i in val: print(i, end=' ') # TypeError: 'int' object is not iterable

it = iter(dic)
while True:
    try:
        I = next(it)
        print(i, end=' ')
    except StopIteration:
        break

from random import random 
class RandomIterator:
    def __init__(self, k):   #initiate random sequence
        self.k = k              # number of random element
        self.i = 0              # counter
    def __iter__(self):      # method iter
        return self             # return intself
    def __next__(self):      # method next
        if self.i < self.k:     # check that we can calculater next object
            self.i += 1         # increade counter
            return random()     # fetch next object
        else:
            raise StopIteration # raise an error at the end of iterations

for x in  RandomIterator(3): print(x)
   #  0.7976183493606193
   #  0.002919405699900457
   #  0.6408160157614484

from random import random 
def random_generator(k):
    for i in range(k):
        yield random()

gen=random_generator(3)
for i in gen:
    print(i)
 # 0.7074683969601196
 # 0.2222520326598939
 # 0.23386693884925625