while Loop
The standard while conditional loop statement is similar to the if. Again, as with every code sub-block, indentation (and dedentation) are used to delimit blocks of code as well as to indicate which block of code statements belong to:
while
expression:
while_suite
The statement suite is executed continuously in a loop until the expression becomes zero or false; execution then continues on the first succeeding statement.
>>> counter = 0
>>> while counter < 5:
… print 'loop #%d' % (counter)
… counter = counter + 1
loop #0
loop #1
loop #2
loop #3
loop #4
loop #5
Loops such as while and for (see below) are covered in the loops section of Chapter 8.