SciPy Constant

The scipy.constant package is available with a wide range of constants, which is used extensively in the scientific field. There are various physical, mathematical constants and units that we can import the required constants and use them as per needed.

List of Mathematical constant

The scipy.constant provides the following list of mathematical constants.

Sr. No.	Constants	Description
1.	pi	pi
2.	golden	Golden ratio

Consider the following example of scipy.constant. Here we compare the 'pi' value by importing different modules.

#Import pi constant from the scipy 
from scipy.constants import pi
#Import pi from math package
from math import pi
#Comparing these two pi value
print("sciPy - pi Value = %.18f"%scipy.constants.pi)
print("math - pi Value = %.18f"%math.pi)

Output:

The above code will give the following output. As we can observe that both values are same.

sciPy - pi Value = 3.141592653589793116
math - pi Value = 3.141592653589793116

Physical Constants

The scipy.constant package provides the number of physical constants. The most commonly used physical constants are the following:

Sr. No.	Physical Constants	Description
1.	c	Speed of light in vaccum
2.	speed_of_light	Speed of light in vaccum
3.	G	Standard acceleration of gravity
4.	G	Newton Constant of gravitation
5.	E	Elementry charge
6.	R	Molar gas constant
7.	Alpha	Fine-structure constant
8.	N_A	Avagadro constant
9.	K	Boltzmann constant
10	Sigma	Stefan-Boltzmann constant σ
11.	m_e	Electron mass
12.	m_p	Proton mass
13.	m_n	Neutron Mass
14.	H	Plank Constant
15.	Plank constant	Plank constant h

Other important Constant

It is difficult to remember all units; the few essential constants are listed below:

Sr. No.	Units	Value
1.	Mass
	Gram	One gram in Kilogram.
	Grain	One grain in Kilogram.
	Pound	One Pound in Kilogram.
	Ounce	One Ounce in Kilogram.
	automic_mass	Atomics mass constant in Kilogram.
2.	Time
	Minute	One minute in seconds.
	Hour	One hour in seconds.
	Day	One day in seconds.
	Year	One year in seconds.
3.	Length
	Inch	One inch in meters.
	Foot	One foot in meters.
	Yard	One yard in meters.
	Pt	One point in meters.
	Micron	One Micron in meters.
4.	Pressure
	Atm	The standard atmosphere in pascals.
	Atmosphere	The standard atmosphere in pascals.
	Bar	One bar in Pascals.
	Torr	One torr(mmHg) in pascals.
5.	Area
	Hectare	One hectare in square meters.
	Acre	One acre in square meters.
6.	Speed
	Kmh	Kilometer per hour in meter per second.
	Mph	Miles per hour in meter per second.
	Mach	One Match in meter per second.

The scipy.constant provides the find() function, which returns a list of physical_constant keys containing a given string.

Consider the following example:

from scipy.constants import find, physical_constants
find('boltzmann')

Output:

['Boltzmann constant',
 'Boltzmann constant in Hz/K',
 'Boltzmann constant in eV/K',
 'Boltzmann constant in inverse meters per kelvin',
 'Stefan-Boltzmann constant']

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