Page 245 - Computer Science Class 11 With Functions
P. 245

Note that the range()  function returns an immutable sequence of values and that the control variable i  takes
            values from this sequence. So, changing the value of the control variable in the body of the for statement does not
            change the flow of execution of the for statement.
            10.3.5 More Examples of for Statement

            In Table 10.2, we give some more examples of the use of the for statement:
                                                Table 10.2: Statements using for loop

                            Statements                          Output                       Description

             for ch in 'ABCD':                          A                        The control  variable ch takes each
                 print(ch)                              B                        value  in  the  sequence  of  characters:
                                                        C                        'A', 'B', 'C', 'D'
                                                        D
             numbers = [9, 0, -4, 23, 17, 56]           0                        The control variable n takes  values

             for n in numbers:                          -4                       in the list numbers, one by one. For
                                                                                 each  value of the  control variable,
                if n%2 == 0:                            56
                                                                                 n, from the list  numbers, print
                   print(n)                             Job Done
                                                                                 statement is executed if n%2 == 0.
             print('Job Done')
                                                                                 The statement print('Job Done')
                                                                                 is  not  part of  the body  of  the loop,
                                                                                 so  it  is  executed  after  the  loop
                                                                                 terminates.

             for x in range(30, 50, 5):                 30                       The control variable, x, takes values in
                print(x)                                35                       the range of 30 to 50 (excluding 50) in
                                                                                 steps of 5.
                                                        40
                                                        45
             for p in range(4):                         0 1 2 3                  The control  variable p takes  values
                print(p,  end=' ')                                               in the sequence 0, 1, 2, 3. The default
                                                                                 start value is 0.
             for p in range(100, 90, -2):               100 98 96 94 92 BYE As the body of the for loop is executed,
                print(p, end=' ')                                                the numbers in the range of 100 to 91
             else:                                                               (in steps of -2) are printed. The else
                                                                                 part of the for loop is executed after
                print("BYE")
                                                                                 all  iterations  of  the  loop  have  been
                                                                                 executed.
             for c in 'ROSE':                           Good Code                For each value of the control variable
                 if c == 'O':                           O                        c in  the  string  'ROSE', the if-else
                                                                                 statement is executed.
                     print(c)                           Good Code
                 else:                                  Good Code
                     print('Good Code')
             for c in 'ROSE':                           O                        For each value of the control variable c
                 if c == 'O':                           Good Code                in the string 'ROSE' the if statement
                                                                                 is  executed.  The  else clause  is
                     print(c)
                                                                                 part of  the  for statement, and  it  is
             else:
                                                                                 executed after all iterations of the for
                 print('Good Code')
                                                                                 statement have been completed.





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