Python math pi constant

Python math.pi Constant

The math.pi constant returns the value of PI: 3.141592653589793. The math.pi constant is defined as the circumference ratio to the diameter of a circle.

How to Use Pi in Python?

There are the following ways you can use the pi in Python

1. Method 1: Using math.pi
2. Method 2: Using np.pi
3. Method 3: Using scipy.constants.pi

Method 1: Using math.pi

To use Pi in Python, import the math module and use it as math.pi.

Syntax

Return Value

It returns a float value that is the value of the mathematical constant “PI“.

How to import pi in Python?

To import pi in Python, import the math module and then use the math.pi constant.

import math print('The value of pi is: ', math.pi)

The value of pi is: 3.141592653589793

You can also use the numpy module. Math is a built-in Python module, and numpy is a third-party library for array computation.

Math constants in Python

It returns the value of pi: 3.141592653589793

It returns the value of the natural base e., e is 0.718282

It returns the value of tau. tau = 6.283185

It returns Not a number type.

Method 2: Using np.pi

To find a pi in Python without the math module, use the np.pi() function. The np.pi() is a numpy library function that returns the value of pi.

Syntax

Example

import numpy as np print(np.pi)

Method 3: Using scipy.constants.pi

The scipy library in Python provides functionality for numerical computations, including calculating mathematical constants like Pi. For example, the constant pi is available in the scipy.constants module.

Syntax

Example

import scipy.constants as constants print("Pi (scipy): ", constants.pi)

Pi (scipy): 3.141592653589793

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Using Pi in Python (NumPy and Math)

In this tutorial, you’ll learn how to get and use the value of pi in Python. We’ll explore a number of different ways in which you can get and store the value of pi in Python. First, we’ll look at the math library, followed by the NumPy library. We’ll explore why you may want to choose one way over the other and close out with a fun alternative way of generating the value.

What is the Pi Constant?

The number pi, π, is a mathematical constant that’s approximately equal to 3.14159. It’s commonly used in Euclidian geometry to represent the ratio of a circle’s circumference to its diameter.

Pi itself is an irrational number, meaning that the value cannot be represented as a common fraction. However, the fraction 22/7 is often used to represent its value as an approximation. Similarly, the decimal representation of the value never ends and never moves into a permanently repeating pattern.

Now that you have a good understanding of the nature and uses of pi, let’s see how we can get this important mathematical constant in Python!

Get Pi in Python Using Math

In this section, you’ll learn how to use the math library to get the value of pi in Python. Because the math library is part of the standard Python library, you don’t need to install anything additional. Let’s see how we can import the value:

# Using math to Get the Value of Pi import math pi = math.pi print(pi) # Returns: 3.141592653589793

We can see that the constant pi is available simply by accessing the constant in the library.

If you’re only planning on using the constant from the library, it may make sense to import only that constant, rather than the whole library. This can be done as shown below:

# Only Importing Pi from Python math from math import pi pi_value = pi print(pi_value) # Returns: 3.141592653589793

This allows you to use the constant without needing to reference the library. In the next section, you’ll learn how to use the NumPy library to access the value of pi.

Get Pi in Python Using NumPy

Similar to the math library, the Python NumPy library provides the value of the pi constant. Since NumPy isn’t part of the standard Python library, you may need to install it. This can be done by using either pip or conda , as shown below:

$ pip install numpy $ conda install numpy

Use either one of these installation methods, depending on your preferred package manager.

Once the library is installed, we can access the value of pi by using the constant in the library:

# Getting the Value of Pi in NumPy import numpy as np pi_value = np.pi print(pi_value) # Returns: 3.141592653589793

This method works similarly to how we would use the math library. Similarly, we can simply import the constant directly, if we only intend to use that value and nothing else from the library:

# Only Importing Pi from Python numpy from numpy import pi pi_value = pi print(pi_value) # Returns: 3.141592653589793

In the next section, we’ll explore when it’s better to use one method over the other.

Should You Use NumPy or Math to Get Pi in Python?

So far, you’ve learned two different ways to access the value of pi . At this point, you may be wondering which method is better to use. Before diving into that discussion, let’s first take a look if the value of the two constants is equal.

We can do this by using the == comparison operator:

# Comparing the two methods of getting pi in Python import math import numpy as np math_pi = math.pi numpy_pi = np.pi print(math_pi == numpy_pi) # Returns: True

Using the code above, we can see that the two values are the same. So, when would you use one over the other?

Because the math library is part of the standard Python library, using this approach means you’re not loading any additional dependencies. However, if you’re working with numerical calculations, there’s a good chance you’re using numpy already. In this case, it may be more straightforward simply to use the numpy approach.

So, in conclusion, the best method to use is the one that’s most useful to your circumstance. If you’re already using numpy in your program, you’re better off just using numpy’s pi constant. If you’re not using numpy, however, and want to keep your dependencies low, then you should use math .

Get Pi in Python Using Radians

Another fun way that you can get the value of pi in Python is to use the radians() function from the math library. When you pass in 180 as the value for the radian, the function returns the value of pi.

Let’s see what this looks like:

# Getting the Value of Pi with Radians import math pi = math.radians(180) print(pi) # Returns: 3.141592653589793

While this isn’t the most practical way to get the value of pi, it does work!

Conclusion

In this tutorial, you learned how to use Python to get the value of pi. You first learned about some of the basic properties of pi and why you may need a library to access its value. You then learned how to use both the math and numpy packages to get the value of pi. Finally, you learned how to use the radians() function to get the value of pi.

Additional Resources

To learn more about related topics, check out the articles below:

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How to use pi in Python?

In this guide, we learn how to use pi in Python. We also look at the pros and cons of all the methods that can be used.

Table of Contents

Pi in Python:

Pi (π) is a mathematical constant that is defined as the ratio of a circle’s circumference to its diameter. Given Python is extensively used in the field of mathematics, it extends support to multiple mathematical constants including pi.

There are multiple methods to use the Pi constant in Python. However, most of these methods would involve importing a module. In this tutorial, we look at the most common and well-documented methods.

Using math.pi

This method belongs to the mathematical module in Python. This module extends support to numerous mathematical constants and functions. A few commonly used constants are math.pi, math.e and math.tau.

Let us look at the syntax of math.pi()

This method returns a float value that is equivalent to the pi constant (3.141592653589793).

Code and Explanation:

The math module needs to be imported in order to use the pi methods.

# Importing math Library import math # Print pi in Python using the math module print (math.pi) 

Using numpy.pi:

The numpy.pi is a method that is very similar to the previous method. However, rather than use the math modules we are using numpy. Numpy or Numerical Python is a very powerful package in Python that is commonly used by data professionals.

We use the pi methods within this package to use pi in Python. The syntax is quite similar to the earlier method.

Similarly, this method also returns a float value equivalent to the pi constant.

Code and Explanation:

# Importing Numpy Library import numpy # Print pi in Python using the math module print (numpy.pi) 

Closing thoughts — Pi in Python:

Both these methods work the same way. However, given it relates to mathematics the module you chose to work with would depend on your use case. If you are looking to work on large sets of data with numerous calculations I would recommend using numpy. If not, the math module would be a good choice.

There are other modules that help you achieve this as well. However, these methods are the most commonly used. In case you are curious to know more you can take a look at the scipy.pi methods from the scipy module.

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Using pi(π) in Python — math.pi Constant

and the value of pi(π) is 3.141592653589793.

If we want to use this value of pi(π) for calculations in Python programming, we can do so by importing the math library, or by importing the numpy library.

The math library contains a method called pi, using which we can easily access the value of pi(π) and use it for calculations in Python programming.

Method 1 — import math library

Here is how we can import the math library and use pi in Python —

import math pi = math.pi print(pi)

The Output will be —

Using the above code, we import all the methods of the math library. And at line #3, we specifically store the value of the pi method from the math library into our pi variable.

Method 2 — from math import pi

Another simple way to use pi in Python by importing the math library is as follows —

from math import pi print(pi)

The Output will be —

Using the above code, we only import the pi and do not import any other methods of math library.

Method 3 — from numpy import pi

We can also use the numpy library to access the value of pi in Python. Here’s an example:

from numpy import pi # Here we print the value of pi print(pi) # Here we calculate the area of a circle with radius 3 using pi radius = 3 area = pi * radius ** 2 print(area)

The Output will be —

Using the above code, we only import the pi and do not import any other methods of numpy library.

Example of Using pi(π) from math class in Python

Let’s find the area and circumference of a circle whose diameter is 10 in Python Programming.

Here is the Python code for this example-

from math import pi diameter = 10 # We know, area of a circle = π(r*r) # and circumference of a circle = 2πr # r is the radius and r = diameter/2 radius = diameter/2 area = pi*(radius*radius) circumference = 2*pi*radius print('Area of the circle is : ', area) print('Circumference of the circle is : ', circumference)

The Output will be —

Area of the circle is : 78.53981633974483
Circumference of the circle is : 31.41592653589793

Using math.pi constant, or importing pi from the math library, is extremely necessary while we are solving mathematical problems in Python programming.

Conclusion

Both the math and numpy libraries provide access to the value of pi in Python, and we can choose the one that is better suited for our specific use case.

I hope the article was helpful.

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About the Author

This article was authored by Rawnak.

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