scipy.constants module

Introduction

The scipy.constants module gives you easy access to many important scientific constants. This helps you avoid typing numbers manually and reduces mistakes.

When you need the speed of light value for physics calculations.

When calculating energy using Planck's constant.

When converting units using constants like the Boltzmann constant.

When you want to use the gravitational constant in astronomy problems.

When you need standard constants for chemistry or engineering formulas.

Syntax

SciPy

from scipy import constants

# Access a constant by name
value = constants.constant_name

Replace constant_name with the exact name of the constant you want.

Constants are typically stored as floats with high precision.

Examples

This gets the speed of light in meters per second and prints it.

SciPy

from scipy import constants

speed_of_light = constants.c
print(speed_of_light)

This gets Planck's constant in joule seconds.

SciPy

from scipy import constants

planck = constants.Planck
print(planck)

This gets Avogadro's number, useful in chemistry.

SciPy

from scipy import constants

avogadro = constants.Avogadro
print(avogadro)

Sample Program

This program prints five important scientific constants using scipy.constants. It shows how easy it is to get accurate values for common constants.

SciPy

from scipy import constants

# Print some common constants
print(f"Speed of light (m/s): {constants.c}")
print(f"Planck's constant (J s): {constants.h}")
print(f"Boltzmann constant (J/K): {constants.k}")
print(f"Gravitational constant (m^3/kg/s^2): {constants.G}")
print(f"Avogadro's number: {constants.N_A}")

Important Notes

All constants follow the latest CODATA recommended values.

You can find a full list of constants in the official SciPy documentation.

Some constants represent exactly defined values, like the speed of light in vacuum.

Summary

scipy.constants provides easy access to many scientific constants.

Use it to avoid errors and save time when working with physics or chemistry formulas.

Just import and call the constant by its exact name.