I'm not able to exit my while loop...

When you answer yes the first time, variable question is updated to the condition of your loop before the loop so the loop exits. However if you answer no and the loop is allowed to execute there is no code that updates variable question within the loop. So it will run forever. The following fixes that:

name = input("What's your name? ")
question = ""
while (question != "yes"):
    question = input("Do you understand Python while loops? ")
print("Now you get it {}".format(name))

KRIS rightly addresses the issue, you are expecting a particular answer, you will not exit the loop until you've found that answer. You use something like:

name = input("What's your name? ")

question = "Do you understand Python while loops? {}, (Yes/No)".format(name)

while True:

    answer = input(question)

    if answer.lower() == 'yes':
        print("That's great, Python is a great language {}".format(name))
        break
    elif answer.lower() == 'no':
        print("You must learn python, it's a great language {}".format(name))
        break
    else:
        print("You didn't enter correct answer {}, try again".format(name))
        continue

The loop will break whether the answer is a yes or a no, otherwise it will indicate to the user that the answer is not what is expected and it will keep looping until a 'yes' or a 'no' is received.