Python Constant

What is Constant?

Constants are variables whose values have to not be changed all through the execution of a software.

Unlike a few other programming languages, Python would not have a integrated consistent key-word. Instead, programmers use naming conventions to suggest that a variable is intended to be treated as a steady.

Naming Convention for Constants:

By convention, names of constants in Python are written in uppercase with underscores to separate phrases. This convention helps distinguish constants from regular variables.

                                  
                                    PI = 3.14159
GRAVITY_ACCELERATION = 9.8

Using Constants:

Once a variable is declared with an uppercase call and assigned a price, it is handled as a constant. Attempting to reassign a price to a regular will increase a SyntaxError or really not be considered good exercise.

                                  
                                    PI = 3.14159
PI = 3.14  # This will raise a SyntaxError or not be considered good practice

Complex Numbers (complex):

Complex numbers have a real component and an imaginary component. They are written within the shape a bj, wherein a is the real part, b is the imaginary component, and j is the imaginary unit.

                                  
                                    z = 3 + 2j

Why Use Constants?

Readability: Constants with significant names enhance code clarity. Readers without delay recognize that the price have to not be changed.
Maintainability: If a consistent value needs to be modified, modifying it in a single vicinity (the declaration) ensures that the alternate propagates in the course of the code.
Prevention of Bugs: Using constants prevents unintended amendment of values that need to remain constant, decreasing the chance of insects.

Example:

                                  
                                    # Define constants
MAX_VALUE = 100
MIN_VALUE = 0

# Using constants in calculations
user_input = 75
if MIN_VALUE <= user_input <= MAX_VALUE:
    print("Input within valid range")
else:
    print("Invalid input")

In this example, MAX_VALUE and MIN_VALUE act as constants defining the legitimate variety for person enter.

While Python does not put into effect the immutability of variables categorised as constants, adhering to the naming conference and treating them as such facilitates maintain code integrity and readability.