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
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.
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,
Xare different variables.
- Python has a number of reserved words that cannot be used as variable names, such as
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
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.