The while statement allows you to repeatedly execute a block of
		statements as long as a condition is true. A while statement is an
		example of what is called a looping statement. A
		while statement can have an optional else clause.
		
		
Example 6.2. Using the while statement
#!/usr/bin/python # Filename: while.py number = 23 running = True while running: guess = int(raw_input('Enter an integer : ')) if guess == number: print 'Congratulations, you guessed it.' running = False # this causes the while loop to stop elif guess < number: print 'No, it is a little higher than that.' else: print 'No, it is a little lower than that.' else: print 'The while loop is over.' # Do anything else you want to do here print 'Done'
$ python while.py Enter an integer : 50 No, it is a little lower than that. Enter an integer : 22 No, it is a little higher than that. Enter an integer : 23 Congratulations, you guessed it. The while loop is over. Done
				
				In this program, we are still playing the guessing game, but the advantage
				is that the user is allowed to keep guessing until he guesses correctly -
				there is no need to repeatedly execute the program for each guess as we
				have done previously. This aptly demonstrates the use of the
				while statement.
				
				
				
				We move the raw_input and if
				statements to inside the while loop and set the
				variable running to True before
				the while loop. First, we check if the variable running
				is True and then proceed to execute the corresponding
				while-block. After this block is executed, the
				condition is again checked which in this case is the running
				variable. If it is true, we execute the while-block again, else we continue
				to execute the optional else-block and then continue to the next statement.
				
				
				
				The else block is executed when the while
				loop condition becomes False - this may even be the first
				time that the condition is checked. If there is an else
				clause for a while loop, it is always executed unless you
				have a while loop which loops forever without ever breaking
				out!
				
				
				
				The True and False are called Boolean
				types and you can consider them to be equivalent to the value
				1 and 0 respecitvely. It's important
				to use these where the condition or checking is important and not the actual
				value such as 1.
				
				
				
				The else-block is actually redundant since you can put those statements
				in the same block (as the while statement) after the
				while statement to get the same effect.
				
				
					
					Remember that you can have an else clause for
					the while loop.