In this article, we will look at while loops in Python. In the above code, the loop will stop execution when x is 5, in spite of x being greater than or equal to 1. The above code is an example of an infinite loop. But as you learn to write efficient programs, you will know when to use what. The while loop in python first checks for condition and then the block is executed if the condition is true. while expression: statement(s) Here, statement(s) may be a single statement or a block of statements with uniform indent. You can add an "else" statement to run if the loop condition fails. The while loop starts only if the condition evaluates to True. The while loop will run as long as the conditional expression evaluates to True. If you initialise x as 20, the loop will never execute. Python break Statement for Loop – While & For, Python remove single quotes from a string | (‘), Python Programming Language | Introduction, Python Append File | Write on Existing File, Convert string to int or float Python | string to number, Python try except | Finally | Else | Print Error Examples, Raise an exception with custom message | Manually raising, Dynamically set image src using JavaScript | Simple HTML Example code, JavaScript get image source from img tag | HTML Example code, Change element tag name JavaScript | Using Pure JS Example, JavaScript get element by tag Method | Simple Example code, JavaScript get element by name Method | Example code. The above code runs the "run_commands()" function once before invoking the while loop. However, you want to continue subsequent executions until the main while condition turns false. Syntax of while Loop in Python It is also known as a pre-tested loop. We also have thousands of freeCodeCamp study groups around the world. Python – While loop example. The while loop will check the condition every time, and if it returns "true" it will execute the instructions within the loop. When x is 11, the while condition will fail, triggering the else condition. Compound statements - The while statement — Python 3.9.1 documentation; This post describes the following contents. while True means loop forever. Here's another scenario: say you want to skip the loop if a certain condition is met. A while loop might not even execute once if the condition is not met. There are two variations of the while loop – while and do-While. To make the condition True forever, there are many ways. Recall that a while True block repeats the code inside it indefinitely. This may be when the loop reaches a certain number, etc. Q: What does “while True” mean in Python? Program (repeat_message.py) # This program print message 5 times. If you are learning to code, loops are one of the main concepts you should understand. The while loop has two variants, while and do-while, but Python supports only the former. For and while are the two main loops in Python. Let's try the do-while approach by wrapping up the commands in a function. The while loop in Python is used to iterate over a block of code as long as the test expression (condition) is true. Syntax of while Loop in Python while test_expression: Body of while This post describes a loop (repeated execution) using while statement in Python.. Usage in Python. To learn more about for loops, check out this article recently published on freeCodeCamp. The while statement takes an expression and executes the loop body while the expression evaluates to (boolean) "true". Answer: That’s very debatable, while (true) is not a good idea because it makes it hard to maintain this code. Loops help you execute a sequence of instructions until a condition is satisfied. The concept behind a while loop is simple: While a condition is true -> Run my commands. Here is the general format of the while loop in Python. While the loop is skipped if the initial test returns FALSE, it is also forever repeated infinitely if the expression always returns TRUE.. For example, while loop in the following code will never exit out of the loop and the while loop will iterate forever. Now let's write some code. Python Infinite While Loop. In spite of being present in most of the popular programming languages, Python does not have a native do-while statement. Let's add an else condition to our code to print "Done" once we have printed the numbers from 1 to 10. If you are not careful while writing loops, you will create infinite loops. Python While True creates an infinite loop and in other languages that use while. check out this article recently published on freeCodeCamp. Our mission: to help people learn to code for free. Loops are one of the most useful components in programming that you will use on a daily basis. 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