It is still true, so the body executes again, and In the example above, when the loop is encountered, In each example you have seen so far, the entire body of the About now, you may be thinking, “How is that useful?” You could accomplish the same thing by putting those statements immediately after the In this case, the loop repeated until the condition was exhausted: One of the following interpretations might help to make it more intuitive:If you don’t find either of these interpretations helpful, then feel free to ignore them.First of all, lists are usually processed with definite iteration, not a Secondly, Python provides built-in ways to search for an item in a list.

A while loop statement in Python programming language repeatedly executes a target statement as long as a given condition is true.. Syntax. The while loop in Python is used to iterate over a block of code as long as the test expression (condition) is true. Leave a comment below and let us know.Almost there! Usage in Python. You’ll be able to construct basic and complex while loops, interrupt loop execution with break and continue, use the else clause with a while loop, and deal with infinite loops. When the condition becomes false, program control passes to the line immediately following the loop.In Python, all the statements indented by the same number of character spaces after a programming construct are considered to be part of a single block of code. With the while loop we can execute a set of statements as long as a condition is true. Its construct consists of a block of code and a condition. Python uses indentation as its method of grouping statements.Here, key point of the while loop is that the loop might not ever run. while expression: statement(s) Here, statement(s) may be a single statement or a block of statements. The syntax of a while loop in Python programming language is −. Thus, you can specify a You should now have a good grasp of how to execute a piece of code repetitively.John is an avid Pythonista and a member of the Real Python tutorial team.What’s your #1 takeaway or favorite thing you learned? This results in a loop that never ends. How are you going to put your newfound skills to use? Just remember that you must ensure the loop gets broken out of at some point, so it doesn’t truly become infinite.In general, Python control structures can be nested within one another.

Print i as long as i is less than 6: i = 1 while i 6: print(i) i += 1. We generally use this loop when we don't know the number of times to iterate beforehand. As the for loop in Python is so powerful, while is rarely used, except in cases … You must use caution when using while loops because of the possibility that this condition never resolves to a FALSE value. For example, In fact, all the Python control structures can be intermingled with one another to whatever extent you need.

That is as it should be. Here we use the for loop to loop through the word computer. While loops, like the ForLoop, are used for repeating sections of code - but unlike a for loop, the while loop will not run n times, but until a defined condition is no longer met. Python has two primitive loop commands: while loops; for loops; The while Loop. Happily, you won’t find many in Python.This only works with simple statements though.

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If the condition is initially false, the loop body will not be executed at all.

When the condition is tested and the result is false, the loop body will be skipped and the first statement after the while loop will be executed.When the above code is executed, it produces the following result −The block here, consisting of the print and increment statements, is executed repeatedly until count is no longer less than 9. For example, you might write code for a service that starts up and runs forever accepting service requests. The condition may be any expression, and true is any non-zero value. You can use the You will learn about exception handling later in this series.Maybe that doesn’t sound like something you’d want to do, but this pattern is actually quite common. Imagine how frustrating it would be if there were unexpected restrictions like “A Seemingly arbitrary numeric or logical limitations are considered a sign of poor program language design. Syntax of while Loop in Python while test_expression: Body of while. In programming, there are two types of iteration, indefinite and definite:When you’re finished, you should have a good grasp of how to use indefinite iteration in Python.When the body of the loop has finished, program execution returns to the top of the loop at line 2, and the expression is evaluated again. Such a loop is called an infinite loop.An infinite loop might be useful in client/server programming where the server needs to run continuously so that client programs can communicate with it as and when required.When the above code is executed, it produces the following result −Above example goes in an infinite loop and you need to use CTRL+C to exit the program.The following example illustrates the combination of an else statement with a while statement that prints a number as long as it is less than 5, otherwise else statement gets executed.When the above code is executed, it produces the following result −It is better not try above example because it goes into infinite loop and you need to press CTRL+C keys to exit.

In this tutorial, you'll learn about indefinite iteration using the Python while loop. The while loop tells the computer to do something as long as the condition is met. With each iteration, the current value of the index count is displayed and then increased by 1.A loop becomes infinite loop if a condition never becomes FALSE. Example. When do I use them? Loop through words. word = "computer" for letter in word: print letter Output c o m p u t e r While Loop. While loops.