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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)
In the above example, round() function is used to round a floating-point number to a specified number
of decimal places.
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 = 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 (_), N1, etc.
Variable names are case-sensitive.
Variable names cannot contain any special character or symbol.
Introduction to Programming 105

