If you already know the working of for Loop, then understanding the while Loop will be very easy for you. If you delete the line counter = counter + 1 from our while loop, it will run forever: it never goes above 0, so the indented code runs over and over again. Previously, you learned how to write loops that read and process a sequence of values. The while loop is also useful in running a script indefinitely in the infinite loop. The else block with while loop gets executed when the while loop terminates normally. How works nested while loop. Print i as long as i is less than 6: i = 1 while i 6: print(i) i += 1 Leaving aside whether this loop is a good way to solve your larger problem, one reason your current while loop is not ever ending is because you've messed up the condition. Flowchart of while Loop Flowchart for while loop in Python Example: Python while Loop A loop that uses a sentinel value is called a sentinel-controlled loop. But unlike while loop which depends on … Sometimes you may want to use a ‘break’ statement to end the loop when a specific condition is met. None and 0 are interpreted as False. Python interprets any non-zero value as True. In the nested-while loop in Python, Two type of while statements are available:Outer while loop; Inner while loop; Initially, Outer loop test expression is evaluated only once.. Let’s create a small program that executes a while loop. The body starts with indentation and the first unindented line marks the end. In this program, we’ll ask for the user to input a password. A sentinel value denotes the end of a data set, but it is not part of the data. Example. In Python, the body of the while loop is determined through indentation. Python while Loop: In the previous article, we have briefly discussed the for Loop in Python.. Now, it’s time to move to the next and last type of Loop statement which is while Loop. This continues till x becomes 4, and the while condition becomes false. Today you will learn about while loops with sentinel values. With the while loop we can execute a set of statements as long as a condition is true. When its return true, the flow of control jumps to the inner while loop. Python While Loops Previous Next Python Loops. Just like while loop, "For Loop" is also used to repeat the program. Python while loop is used to run a code block for specific number of times. Watch out for infinite loops when creating a program. Now you know how while loops work, so let's dive into the code and see how you can write a while loop in Python. In Python, while loops are constructed like so: while [a condition is True]: [do something] The something that is being done will continue to be executed until the condition that is being assessed is no longer true. To start, here is the structure of a while loop in Python: while condition is true: perform an action In the next section, you’ll see how to apply this structure in practice. Loops iterate over a block of code until the test expression is false, but sometimes we wish to terminate the current iteration or even the whole loop without checking test expression. How to use "For Loop" In Python, "for loops" are called iterators. Python has two primitive loop commands: while loops; for loops; The while Loop. This is the basic syntax: While Loop (Syntax) These are the main elements (in order): The while keyword (followed by a space). While True → Loop will run forever unless we stop it because the condition of while is always True.. We can stop it using break statement. While Loop. We can use break and continue statements with while loop. 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