Page 169 - Computer Science Class 11 With Functions
P. 169

In the above example, the variable (name), x is accessed for printing its value before it is assigned a value. So, a

            NameError is displayed because the name x is unknown to the interpreter. In the following example, the use of int
            and str objects is incompatible with the + operator, so the interpreter points out a TypeError.
             >>> 10 + "Hello"
                 Traceback (most recent call last):
                   File "<pyshell#1>", line 1, in <module>
                     10 + "Hello"
                 TypeError: unsupported operand type(s) for +: 'int' and 'str'


                     Match the following:
                     1.  Implicit type conversion          a.  Infinite loop
                     2.  Syntax Error                      b.  Trying to read a file that does not exist
                     3.  Logical Error                     c.  y = int(input("Enter a number"))
                     4.  Explicit Type conversion          d.  PRINT()
                     5.  Runtime Error                     e.  coercion


            Common Errors

            ● Missing quotation marks for strings
            print(India)  # string value not enclosed in quotation marks

            ● Not using the same quotation marks before and at the end of the string
            print("India')
            print('India")
            # the string not enclosed within same type of quotation marks
            ● Copying a string from a word processor, For example,

             >>> print(‘India’)
                 SyntaxError: invalid character ''' (U+2018)
                 Also, observe the following,
             >>> ord("'")
                 39
             >>> ord("’")
                 8217
             >>> ord("‘")
                 8216
            ● Not using correct brackets for data types

                myList = (1,2,5,9)
            # The programmer wanted to create a list, but produced a tuple.



                 Let's Summarise


              Ø   A data type denotes a set of specific type of values. For example, the data type int includes negative and
                  non-negative integers.
              Ø   A numeric data type  can store  only  numbers or numeric values on  which  arithmetic operations  can be
                  performed.
              Ø   Numeric data type may be: int, float, and complex.
              Ø   bool or Boolean data type consists of two possible values: True and False.



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