How to Use Pi in Python?

You can use the mathematical constant Pi (π) in Python primarily through the math and numpy libraries. Here's how:

1. Using the math Library

The math library is part of Python's standard library, so you don't need to install it separately.

import math

# Access Pi using math.pi
pi_value = math.pi

print(pi_value)  # Output: 3.141592653589793

• import math: Imports the math module.
• math.pi: Accesses the value of Pi stored in the math module.

2. Using the numpy Library

If you are doing numerical computations, especially with arrays, numpy is often a preferred choice. You'll need to install it if you haven't already (pip install numpy).

import numpy as np

# Access Pi using numpy.pi
pi_value = np.pi

print(pi_value)  # Output: 3.141592653589793

• import numpy as np: Imports the numpy module and gives it the alias np.
• np.pi: Accesses the value of Pi stored in the numpy module.

Example: Calculating the Area of a Circle

Here's how you can use Pi to calculate the area of a circle:

import math

radius = 5
area = math.pi * radius**2

print(f"The area of a circle with radius {radius} is: {area}")

Or, using numpy:

import numpy as np

radius = 5
area = np.pi * radius**2

print(f"The area of a circle with radius {radius} is: {area}")

Choosing Between math and numpy

• Use math.pi for general mathematical calculations where you don't need numpy's array-based functionality.
• Use numpy.pi when working with numpy arrays or when you're already using numpy for other numerical computations. numpy is often optimized for numerical operations on arrays.