Page 154 - Computer Science Class 11 Without Functions
P. 154

Now, consider the following assignment statement:

         >>> num1 = 100
        It associates a new data object with the name num1 as shown below:
         >>> id(num1)
              1734046275024
         >>> id(num2)
              1734046084944
                                 num1                           50
                                                                          1734046084944





                                 num2                          100
                                                                          1734046275024
                                      Fig 7.4: num1 and num2 refer to different data objects.



        Now let us examine how a mutable object such as a list may be modified.
         >>> lst1 = [30, 60, 10, 20, 50]
         >>> id(lst1)
              1933477279552











                              Fig 7.5: Variable lst1 refers to a list object (object id 1933477279552)
         >>> lst2 = lst1
         >>> id(lst2)
              1933477279552
        Note that each of lst1 and lst2 refers to the same data object.














                       Fig 7.6: Variables lst1 and lst2 refer to the same list object (object id 1933477279552)
        Next, consider the assignment:
         >>> lst1[4] = 100
         >>> lst1
              [30, 60, 10, 20, 100]
         >>> id(lst1)
              1933477279552
        Note that lst1 and lst2 still refer to the same object, as further illustrated below:

         >>> lst2
              [30, 60, 10, 20, 100]
         >>> id(lst2)
              1933477279552

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