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The Problem: While Loops2:15 with Kenneth Love
While loops are used to repeatedly loop through steps "while" a specific condition is true. Let's try this out with some examples.
All right, now let's look at while.py. 0:00 There are only three problems in this one but 0:02 they might prove more difficult than the ones in for.py. 0:05 While loops, 0:07 if you don't remember, will execute until their condition evaluates as false. 0:08 Because of this, they're known as indefinite loops, 0:13 because they can run an indefinite number of times. 0:15 For loops on the other hand, will only run a certain number of times. 0:17 I don't think it's even possible to make infinite for loops in Python. 0:21 You can use the continue keyword to skip an iteration of the loop. 0:24 Or you can use the break keyword to completely stop the loop. 0:28 Both of those keywords work on for loops too, but they're used there less often. 0:31 Let's take a look at the problems. 0:36 The first problem, warm the oven, needs you to add 25 degrees to 0:37 the current oven temperature until it's at 350 degrees. 0:41 On each iteration, print out the current temperature. 0:44 When the loop is done, print out The oven is ready! 0:47 You can use the while loop's else class here if you want. 0:50 For the second problem, you 'll need to finish the function that I started. 0:53 Yeah, I'm gonna call that started. 0:58 Anyway, create an infinite while loop. 1:00 Since while loops run until their condition is false, 1:03 what value could you use to make the condition never false? 1:06 While the loop is running, ask the user for a number and 1:10 add that number to the numbers list. 1:12 If they give you a q, a string q, instead though, end the loop. 1:14 When the loop ends, print out all of the numbers, the sum of the numbers, and 1:19 the average of all of the numbers. 1:22 This solution doesn't absolutely require you to use break, but 1:24 you'll probably find it easier to solve that way. 1:28 Finally, the third problem. 1:31 You might have come across the common programming problem known as fizzbuzz, 1:33 where you have to loop through all of the numbers from say, one to 100. 1:37 And if the number is divisible by 3 or 5 or 7 or some combination of them or 1:40 some other number, then you print out fizz, buzz, or fizzbuzz. 1:45 Now I don't want you to do exactly that, but it's something similar. 1:49 Write a while loop that checks the value of the current variable. 1:52 This one right here called current. 1:56 If it's 101, you should end the loop. 1:58 On each iteration, increment the number by 1. 2:01 If the new number is divisible by 3, 5, 2:04 or both, print it out, otherwise, skip the number. 2:07 All right, see how you do on these challenges. 2:11 And I'll be back with the solutions in a minute. 2:13
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