A variable in Python is a named reference or identifier that stores a value. It acts as a container to hold data during program execution. When you use the assignment operator "
=", you can assign a value to them to create them.
Python interpreter allocates memory based on the values data type of variable, different data types like integers, decimals, characters, etc., can be stored in these variables.
What are Values?
Before learning about variables, you must know about values.
A value is one of the essential parts of a program, like a letter or a number.
Examples of such values can be:
|Hello, Ok||string (a combination of letters)|
Python Variable Declaration
In Python, like many other programming languages, there is no requirement to declare variables in advance explicitly. As soon as a value is assigned to a variable, it is automatically declared at that moment. This characteristic is why Python is known as a dynamically typed language.
The syntax for creating variables in Python is given below:
<variable_name> = <value>
Assigning Values to Variables
Python interpreter can determine what type of data is stored, so variables do not need to be declared before assigning a value.
Usually, in all programming languages, the equal sign "
=" is used to assign values to a variable. It assigns the values of the right-side operand to the left-side operand. The left side operand of the "
=" operator is the name of a variable, and the right side operand is value.
name = "Packing box" # A string height = 10 # An integer assignment width = 20.5 # A floating point print (name) print (height) print (width)
Packing box 10 20.5
In the above code snippet, the variable name "
height" is storing a value "
10", and since the value is of a type integer, the variable is automatically assigned the type integer. Another variable name "
width" is assigned with a floating type value. Then both the values are printed or displayed using the 'print' statement.
Commons Rules for Naming Variables in Python
There are specific rules and conventions regarding variables in Python that must be followed in order to use variables correctly:
- Variable Naming: Variables must follow specific naming conventions. They must begin with letters, numbers, or underscores, followed by other characters. Reserved words should not be used as variable names.
- Case Sensitivity: Variables with different capitalizations are regarded as separate because Python is case-sensitive. For instance, "count" and "Count" are handled differently.
- Avoid Built-in Function Names: It is advised to avoid using the names of built-in functions or modules as variable names to prevent conflicts and confusion.
- Meaningful and Descriptive Names: Use informative names that reflect the variable's purpose or nature. This improves code readability and maintainability.
- Snake Case Convention: Use underscores and lowercase letters to separate words in variable names, adhering to the snake_case convention. For example, "
user_name" or "
- Constants: Constant names typically consist of uppercase letters and underscores. For example, "
PI" or "
Python Variable Deletion
Python also provides a facility to delete a variable from memory. The del command is used for this. The following is the general syntax for deleting a variable in Python: