Python Variables - ideasorblogs

Introduction to Python Variables

In Python, a variable is a named location that stores a value. Variables are used to store values that we can manipulate in our programs.

Declaring a Variable

To create a variable in Python, you just have to give it a name and assign a value to it using the equals sign (=). Here is an example:


x = 5

In this example, we have created a variable called x and assigned it the value 5.

Variable Types

In Python, variables do not have to be explicitly declared. The type of the variable is determined by the value that is assigned to it.

For example:


x = 5  # x is an integer
y = "hello"  # y is a string
z = [1, 2, 3]  # z is a list

You can use the type() function to check the type of a variable.


print(type(x))  # Output: <class 'int'>
print(type(y))  # Output: <class 'str'>
print(type(z))  # Output: <class 'list'>

Variable Naming Rules

Variable names can only contain letters, numbers, and underscores. They cannot start with a number.
Variable names are case-sensitive. For example, x and X are different variables.
Python has a number of reserved words that cannot be used as variable names, such as for, while, if, etc.

Assigning a Value to a Variable

You can assign a value to a variable using the equals sign (=). For example:


x = 5
y = "hello"

You can also assign a value to a variable by using an expression. For example:


x = 5
y = 3
z = x + y  # z is now 8

Reassigning a Value to a Variable

You can change the value of a variable by assigning a new value to it. For example:


x = 5
x = 10  # x is now 10

You can also use variables in expressions to reassign a value to another variable. For example:


x = 5
y = 3
x = x + y  # x is now 8

Conclusion

In this tutorial, we learned about Python variables and how to use them in our programs. We also learned about variable naming rules and how to assign and reassign values to variables.