What are Variables in Python?

 

Variables

What are Variables?

Variables are containers for storing data values.

Variables are used to store values. But the best thing in Python is that, unlike other programming languages, Python has no command for declaring a variable. A variable is created as soon as we assign a value to it.

A variable is created the moment you first assign a value to it.

Example:

x = 5
y = "Computer Gyan Guruji"
print(x)
print(y)

Variables do not need to be declared with any particular type, and can even change type after they have been set.

Example:

x = 4       # x is of type int
x = "Sally" # x is now of type str
print(x)

Casting

If you want to specify the data type of a variable, this can be done with casting.

Example:

x = str(3)    # x will be '3'
y = int(3)    # y will be 3
z = float(3)  # z will be 3.0

Get the Type

You can get the data type of a variable with the type() function.

Example:

x = 5
y = "Computer Gyan Guruji"
print(type(x))
print(type(y))

Variable Names

A variable can have a short name (like x and y) or a more descriptive name (age, carname, total_volume). Rules for Python variables:

• A variable name must start with a letter or the underscore character
• A variable name cannot start with a number
• A variable name can only contain alpha-numeric characters and underscores (A-z, 0-9, and _ )
• Variable names are case-sensitive (age, Age and AGE are three different variables)

Legal variable names:

myvar = "Computer Gyan Guruji"
my_var = "Computer Gyan Guruji"
_my_var = "Computer Gyan Guruji"
myVar = "Computer Gyan Guruji"
MYVAR = "Computer Gyan Guruji"
myvar2 = "Computer Gyan Guruji"

Illegal variable names:

2myvar = "Computer Gyan Guruji"
my-var = "Computer Gyan Guruji"
my var = "Computer Gyan Guruji"

Multi Words Variable Names

Variable names with more than one word can be difficult to read.

There are several techniques you can use to make them more readable:

Camel Case

Each word, except the first, starts with a capital letter:

myVariableName = "Computer Gyan Guruji"

Pascal Case

Each word starts with a capital letter:

MyVariableName = "Computer Gyan Guruji"

Snake Case

Each word is separated by an underscore character:

my_variable_name = "Computer Gyan Guruji"

Many Values to Multiple Variables

Python allows you to assign values to multiple variables in one line:

Example:

x, y, z = "Orange", "Banana", "Cherry"
print(x)
print(y)
print(z)

One Value to Multiple Variables

And you can assign the same value to multiple variables in one line:

Example:

x = y = z = "Orange"
print(x)
print(y)
print(z)

Unpack a Collection

If you have a collection of values in a list, tuple etc. Python allows you to extract the values into variables. This is called unpacking.

fruits = ["apple", "banana", "cherry"]
x, y, z = fruits
print(x)
print(y)
print(z)

Output Variables:

Global Variables:

Variable Exercises:

Python 5:- Watch Video - Click here

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