SciPy Constants Module

SciPy Constants ModuleconstantsProvides many built-in mathematical constants.

Pi is a mathematical constant, the ratio of a circle's circumference to its diameter, approximately equal to 3.14159, commonly represented by the symbolto represent it.

The following example outputs pi:

Example

from scipy import constants

print(constants.pi)

Executing the above code produces the following result:

3.141592653589793

The following example outputs the golden ratio:

Example

from scipy import constants

print(constants.golden)

Executing the above code produces the following result:

1.618033988749895

We can usedir()function to viewconstantswhat constants the module contains:

Example

from scipy import constants

print(dir(constants))

Executing the above code produces the following result:

['Avogadro', 'Boltzmann', 'Btu', ...]

Unit Types

The constants module contains the following types of units:

SI Prefixes

SI prefixes (English: SI prefix) represent multiples and fractions of units. There are currently 20 prefixes, most of which are integer powers of 1000. (centi returns 0.01):

`yotta`	$10^{24}$
`zetta`	$10^{21}$
`exa`	$10^{18}$
`peta`	$10^{15}$
`tera`	$10^{12}$
`giga`	$10^{9}$
`mega`	$10^{6}$
`kilo`	$10^{3}$
`hecto`	$10^{2}$
`deka`	$10^{1}$
`deci`	$10^{-1}$
`centi`	$10^{-2}$
`milli`	$10^{-3}$
`micro`	$10^{-6}$
`nano`	$10^{-9}$
`pico`	$10^{-12}$
`femto`	$10^{-15}$
`atto`	$10^{-18}$
`zepto`	$10^{-21}$

Example

from scipy import constants

print(constants.yotta) #1e+24
print(constants.zetta) #1e+21
print(constants.exa) #1e+18
print(constants.peta) #1000000000000000.0
print(constants.tera) #1000000000000.0
print(constants.giga) #1000000000.0
print(constants.mega) #1000000.0
print(constants.kilo) #1000.0
print(constants.hecto) #100.0
print(constants.deka) #10.0
print(constants.deci) #0.1
print(constants.centi) #0.01
print(constants.milli) #0.001
print(constants.micro) #1e-06
print(constants.nano) #1e-09
print(constants.pico) #1e-12
print(constants.femto) #1e-15
print(constants.atto) #1e-18
print(constants.zepto) #1e-21

Binary Prefixes

Returns byte units (kibi returns 1024).

`kibi`	$2^{10}$
`mebi`	$2^{20}$
`gibi`	$2^{30}$
`tebi`	$2^{40}$
`pebi`	$2^{50}$
`exbi`	$2^{60}$
`zebi`	$2^{70}$
`yobi`	$2^{80}$

Example

from scipy import constants

print(constants.kibi) #1024
print(constants.mebi) #1048576
print(constants.gibi) #1073741824
print(constants.tebi) #1099511627776
print(constants.pebi) #1125899906842624
print(constants.exbi) #1152921504606846976
print(constants.zebi) #1180591620717411303424
print(constants.yobi) #1208925819614629174706176

Mass Units

Returns how many kilogramskg. (gram returns 0.001).

Example

from scipy import constants

print(constants.gram) #0.001
print(constants.metric_ton) #1000.0
print(constants.grain) #6.479891e-05
print(constants.lb) #0.45359236999999997
print(constants.pound) #0.45359236999999997
print(constants.oz) #0.028349523124999998
print(constants.ounce) #0.028349523124999998
print(constants.stone) #6.3502931799999995
print(constants.long_ton) #1016.0469088
print(constants.short_ton) #907.1847399999999
print(constants.troy_ounce) #0.031103476799999998
print(constants.troy_pound) #0.37324172159999996
print(constants.carat) #0.0002
print(constants.atomic_mass) #1.66053904e-27
print(constants.m_u) #1.66053904e-27
print(constants.u) #1.66053904e-27

Angle Units

Returns radians (degree returns 0.017453292519943295).

Example

from scipy import constants

print(constants.degree) #0.017453292519943295
print(constants.arcmin) #0.0002908882086657216
print(constants.arcminute) #0.0002908882086657216
print(constants.arcsec) #4.84813681109536e-06
print(constants.arcsecond) #4.84813681109536e-06

Time Units

Returns seconds (hour returns 3600.0).

Example

from scipy import constants

print(constants.minute) #60.0
print(constants.hour) #3600.0
print(constants.day) #86400.0
print(constants.week) #604800.0
print(constants.year) #31536000.0
print(constants.Julian_year) #31557600.0

Length Units

Returns meters (nautical_mile returns 1852.0).

Example

from scipy import constants

print(constants.inch) #0.0254
print(constants.foot) #0.30479999999999996
print(constants.yard) #0.9143999999999999
print(constants.mile) #1609.3439999999998
print(constants.mil) #2.5399999999999997e-05
print(constants.pt) #0.00035277777777777776
print(constants.point) #0.00035277777777777776
print(constants.survey_foot) #0.3048006096012192
print(constants.survey_mile) #1609.3472186944373
print(constants.nautical_mile) #1852.0
print(constants.fermi) #1e-15
print(constants.angstrom) #1e-10
print(constants.micron) #1e-06
print(constants.au) #149597870691.0
print(constants.astronomical_unit) #149597870691.0
print(constants.light_year) #9460730472580800.0
print(constants.parsec) #3.0856775813057292e+16

Pressure Units

Returns how many Pascals, the SI unit of pressure. (psi returns 6894.757293168361).

Example

from scipy import constants

print(constants.atm) #101325.0
print(constants.atmosphere) #101325.0
print(constants.bar) #100000.0
print(constants.torr) #133.32236842105263
print(constants.mmHg) #133.32236842105263
print(constants.psi) #6894.757293168361

Area Units

Returns how many square meters. A square meter is the metric unit of area, defined as:On a plane, the area of a square with sides of one meter. (hectare returns 10000.0).

Example

from scipy import constants

print(constants.hectare) #10000.0
print(constants.acre) #4046.8564223999992

Volume Units

Returns how many cubic meters. The cubic meter is a unit of volume. The capacity of 1 cubic meter is equivalent to the volume of a cube with length, width, and height all equal to 1 meter. It is equal to the volume of 1 kiloliter and 1 ton of water, and also equal to the volume of 1,000,000 cubic centimeters. (liter returns 0.001).

Example

from scipy import constants

print(constants.liter) #0.001
print(constants.litre) #0.001
print(constants.gallon) #0.0037854117839999997
print(constants.gallon_US) #0.0037854117839999997
print(constants.gallon_imp) #0.00454609
print(constants.fluid_ounce) #2.9573529562499998e-05
print(constants.fluid_ounce_US) #2.9573529562499998e-05
print(constants.fluid_ounce_imp) #2.84130625e-05
print(constants.barrel) #0.15898729492799998
print(constants.bbl) #0.15898729492799998

Speed Units

Returns how many meters per second. (speed_of_sound returns 340.5).

Example

from scipy import constants

print(constants.kmh) #0.2777777777777778
print(constants.mph) #0.44703999999999994
print(constants.mach) #340.5
print(constants.speed_of_sound) #340.5
print(constants.knot) #0.5144444444444445

Temperature Units

Returns how many Kelvin. (zero_Celsius returns 273.15).

Example

from scipy import constants

print(constants.zero_Celsius) #273.15
print(constants.degree_Fahrenheit) #0.5555555555555556

Energy Units

Returns how many joules. The joule (abbreviated as J) is a derived unit of energy, work, or heat in the International System of Units, with the symbol J. (calorie returns 4.184).

Example

from scipy import constants

print(constants.zero_Celsius) #273.15
print(constants.degree_Fahrenheit) #0.5555555555555556

Power Units

Returns how many watts. The watt (symbol: W) is the SI unit of power. One watt is defined as 1 joule per second (1 J/s), i.e., the rate at which energy is converted, used, or dissipated per second (measured in amperes). (horsepower returns 745.6998715822701).

Example

from scipy import constants

print(constants.hp) #745.6998715822701
print(constants.horsepower) #745.6998715822701

Mechanics Units

Returns how many newtons. The newton (symbol: N, English: Newton) is a physical dimension and the metric unit of force. It is named after Isaac Newton, who established classical mechanics. (kilogram_force returns 9.80665).

Example

from scipy import constants

print(constants.dyn) #1e-05
print(constants.dyne) #1e-05
print(constants.lbf) #4.4482216152605
print(constants.pound_force) #4.4482216152605
print(constants.kgf) #9.80665
print(constants.kilogram_force) #9.80665

Other Extensions