Page 116 - ConceptGP_C8_Fb
P. 116

Variables in Python


                 Variables are memory reference points where we store values which can be accessed or
                 changed later. The names given to the variables are known as identifiers. In Python, we do
                 not need to specify the type of variable because Python is a dynamically typed language and
                 it identifies the variable type automatically. Let’s understand this with the help of the given
                 examples.

                     num = 0.4

                     _price = 30.3
                     TOTAL = round(_price * num,2)
                     print(TOTAL)

                 Declaring and Initializing a Variable
                 In Python, variables are declared and initialized at the same time in the following way:

                   a = 10

                   b = 20
                   print ("a=", a)
                   print ("b=", b)
                 On the output screen, a = 10 and b = 20 will be printed. You can also assign the same
                 value to multiple variables at the time in the following way:

                   a = b = 20

                   print ("a=", a)
                   print ("b=", b)
                 On the output screen, a = 20 and b = 20 will be printed.

                 You can also assign multiple values to multiple variables in the same line in the following
                 way:

                   name, age, grade="Deepak", 12, ‘VII’
                   print ("Name is", name)
                   print ("Age is", age)

                   print ("Grade is", grade)
                 On the output screen, Name is Deepak, Age is 12 and Grade is VII will be printed.
                 You must follow the given rules while creating and naming the variables:

                 •   A variable name must start with a letter or underscore character.
                 •   A variable name cannot start with a number.

                 •     A variable name can only contain alphanumeric characters (all the letters of the alphabet
                     and numbers) and underscores (_).
                 •   Variable names are case-sensitive.
                 •     Variable names cannot contain any special character or symbol.





                        114   Premium Edition-VIII
   111   112   113   114   115   116   117   118   119   120   121