Compare this with the do while loop, which tests the condition/expression after the loop has executed. Because the while loop checks the condition/expression before the block is executed, the control structure is often also known as a pre-test loop. This repeats until the condition/expression becomes false.
#Python while loop code
The condition/expression is evaluated, and if the condition/expression is true, the code within all of their following in the block is executed. The while construct consists of a block of code and a condition/expression.
Here are a few examples: # Prints out 0,1,2,3,4 and then it prints "count value reached 5"
Note that the "else" part is executed even if there is a continue statement. Note: Python uses indentation for grouping statements: all statements indented by the same number of spaces after a. It can also be known as the body of the loop.
If a break statement is executed inside the for loop then the "else" part is skipped. A while loop in Python can be created as follows: Example. When the loop condition of "for" or "while" statement fails then code part in "else" is executed. # Prints out only odd numbers - 1,3,5,7,9 The syntax of the while loop is very similar to the if statement, as you can see above. However, as opposed to the if statement, the while loop continues to execute the code repeatedly as long as the condition is True. While loops repeat as long as a certain boolean condition is met. The while loop is somewhat similar to an if statement, it executes the code inside, if the condition is True. Note that the range function is zero based. (Python 3 uses the range function, which acts like xrange). The difference between range and xrange is that the range function returns a new list with numbers of that specified range, whereas xrange returns an iterator, which is more efficient. Here is an example: primes = įor loops can iterate over a sequence of numbers using the "range" and "xrange" functions. The "for" loopįor loops iterate over a given sequence. First, specify the condition as True in the while loop like this: while True : Code language: PHP (php) This allows the code block to execute for the first time. The loop iterates while the condition is true. The condition may be any expression, and true is any non-zero value. However, you can use the while loop and a break statement to emulate the do.while loop statement. The syntax of a while loop in Python programming language is while expression: statement (s) Here, statement (s) may be a single statement or a block of statements. There are two types of loops in Python, for and while. Unfortunately, Python doesn’t support the do.while loop.