SciPy - Constants

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SciPy constants package provides a wide range of constants, which are used in the general scientific area.

SciPy Constants Package

The scipy.constants package provides various constants. We have to import the required constant and use them as per the requirement. Let us see how these constant variables are imported and used.

To start with, let us compare the ‘pi’ value by considering the following example.

#Import pi constant from both the packages
from scipy.constants import pi
from math import pi

print("sciPy - pi = %.16f"%scipy.constants.pi)
print("math - pi = %.16f"%math.pi)

The above program will generate the following output.

sciPy - pi = 3.1415926535897931
math - pi = 3.1415926535897931

List of Constants Available

The following tables describe in brief the various constants.

Mathematical Constants

Physical Constants

The following table lists the most commonly used physical constants.

Units

The following table has the list of SI units.

These units range from yotta, zetta, exa, peta, tera ……kilo, hector, …nano, pico, … to zepto.

Other Important Constants

The following table lists other important constants used in SciPy.

Remembering all of these are a bit tough. The easy way to get which key is for which function is with the scipy.constants.find() method. Let us consider the following example.

import scipy.constants
res = scipy.constants.physical_constants["alpha particle mass"]
print res

The above program will generate the following output.

[
   'alpha particle mass',
   'alpha particle mass energy equivalent',
   'alpha particle mass energy equivalent in MeV',
   'alpha particle mass in u',
   'electron to alpha particle mass ratio'
]

This method returns the list of keys, else nothing if the keyword does not match.