Syntax:
scipy.constants
The scipy.constants package contains several commonly used constants in the scientific computations. A few of them are listed below:
Constant | Description |
---|---|
pi | pi |
golden | Golden ratio |
To use a constant in your Python code, you would use the following syntax:
import scipy
from scipy import constants
print ('The value of constant pi equals', constants.pi)
print ('The value of constant golden ratio equals', constants.pi)
The above code gives following output on the console:
The value of constant pi equals 3.141592653589793
The value of constant golden ratio equals 1.618033988749895
Physical Constants :
The scipy.constant package provides the number of physical constants. The most commonly used physical constants are the following:
Physical Constants | Description |
---|---|
c | Speed of light in vacuum |
G | Standard acceleration of gravity |
E | Elementary discharge |
R | Molar gas constant |
Alpha | Fine structure constant |
N_A | Avogadro constant |
K | Boltzmann constant |
sigma | Stefan-Boltzmann constant σ |
m_e | Electron mass |
m_p | Proton mass |
m_n | Neutron mass |
H | Planck constant |
It is a bit difficult to remember all these constants. But SciPy helps us to find any constant using its find function, Syntax for the same is scipy.constants.find()
. We have to pass a string as parameter and the function will return a list of physical constant keys containing our passed string,
For example:
import scipy.constants
res = scipy.constants.find('boltzmann')
print(res)
Output:
['Boltzmann constant', 'Boltzmann constant in Hz/K', 'Boltzmann constant in eV/K', 'Boltzmann constant in inverse meter per kelvin', 'Stefan-Boltzmann constant']
Units:
Syntax:
scipy.constants.unit
This syntax is used for finding the unit of a constant.
Example:
from scipy import constants
Res = constants.unit(‘proton mass’)
print(res)
The above code gives following output on the console:
Kg
Units | Value |
---|---|
milli | o.oo1 |
micro | 1e - 06 |
Kilo | 1000 |
Above table has the list of SI units These units range from yotta , zetta , exa , peta , tera to Kilo , hector , nano, pico then zepto .
Other important Constants :
Units | Value |
---|---|
Mass | |
Gram | One gram in Kilogram |
Grain | One grain in Kilogram |
Pound | One pound in Kilogram |
Ounce | One ounce in Kilogram |
atomic_mass | Atomic mass constant in Kilogram |
Time | |
minute | One minute in seconds |
Hour | One hour in seconds |
day | One day in a seconds |
year | One year in seconds |
Length | |
inch | One inch in meters |
micron | One micron in meters |
Foot | One foot in meters |
Yard | One yard in meters |
pt | One point in meters |
Light year | One light year in a meters |
Pressure | |
atm | Standard atmosphere in pascals |
Bar | One bar in pascalsn |
Torr | One torr in pascals |
Area | |
acre | One acre in square meters |
Hectare | One hectare in square meters |
Volume | |
liter | One liter in cubic meters |
gallon | One gallon in cubic meters |
Speed | |
kmh | Kilometers per hour in meters per seconds |
mph | Miles per hour in meters per seconds |
Temperature | |
Degree fahrenheit | One fahrenheit in kelvins |
Energy | |
eV | One electron volt in joules |
Power | |
hp | One horse power in watts |
Force | |
dyn | One dyne in newtons |
Angle | |
Degree | Degree in radians |
To use a above constant in your Python code, you would use the following syntax:
import scipy
from scipy import constants
print ('The value of an hour in seconds', constants.hour)
print ('The value of gram in Kilogram', constants.gram)
print ('The value of inch in meter', constants.inch)
Output:
The value of an hour in seconds 3600.0
The value of gram in Kilogram 0.001
The value of inch in meter 0.0254
Likewise you can find values of all constants using this syntax.
The complete list of constants can be found in the SciPy documentation.