The while loop is also known as a pre-tested loop. In general, a while loop allows a part of the code to be executed as long as the given condition is true.
It can be viewed as a repeating if statement. The while loop is mostly used in the case where the number of iterations is not known in advance.
The syntax is given below.
Here, the statements can be a single statement or the group of statements. The expression should be any valid python expression resulting into true or false. The true is any non-zero value.