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    Sometime, we may need to execute a set of statements repeatedly to complete a task. To handle
                     these situations, Python provides the concept of iterative statements. Let us learn about iterative
                     statements in this chapter.

                               ITERATIVE STATEMENTS

                     Iterative statements refer to the statements that are used to repeat a task based on a given
                     condition. These statements are also known as looping statements. Iteration means one pass of
                     a loop.

                     Python provides the following iterative statements:

                     (i)  for loop
                     (ii)  while loop

                     THE for LOOP

                     The for loop allows the user to repeat a set of statements a certain number of times. The for loop
                     is commonly used when the number of iterations is known.
                     The syntax of for loop is as follows:

                     for <counter variable> in range(start, stop, step_size):
                         statements
                     The statements inside the loop must be properly indented. Indentation refers to the spaces at the
                     beginning of a code line. It indicates a block of code. The minimum indentation is one space.

                     The range() function

                     The range( ) function is an in-built function in Python. This function generates a sequence of
                     numbers. A sequence is a succession of values bound together by a single name. The range( )
                     function is generally used in the for loop to iterate over the sequence of numbers.
                     The general syntax for using the range( ) function is given below:

                         range(start, stop, step_size): The start specifies the starting point for generating numbers.
                         By default, it starts from 0. The stop specifies the position up to which the numbers are to be
                         generated (last number is not included). The step_size specifies the increment or decrement.
                         By default, the value of the step_size = 1 and numbers are generated with an increment of
                         1. However, we can generate numbers by specifying the value of step_size according to our
                         requirement.
                         range(start, stop): It generates a set of whole numbers starting from ‘start’ to ‘stop–1’.

                         Example: range(3, 9) is equivalent to [3, 4, 5, 6, 7, 8].
                         range(stop): Generates a set of whole numbers starting from 0 to (stop–1).
                         Example: range(6) is equivalent to [0, 1, 2, 3, 4, 5].

                     The start and step_size values are optional in the application of range() function and they can
                     be omitted.

                                                                                                   Iterations in Python  71

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