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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 initialised at the same time in the following way:

                   a = 10
                   b = 20
                   print ("a=", a)
                   print ("b=", b)

                 On the output screen, a = 20 and b = 40 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.


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