Working with scientific units in python.
Project description
UnitPy (Unit Python)
UnitPy is a Python package for defining, converting, and working with units.
The goal of the package is to be simple, straightforward, and performant.
This package directly implements NIST (National Institute of Standards and Technology) official unit definitions.
Installation
Pip installable package:
pip install unitpy
Requirements / Dependencies
Python 3.7 and up
Basic Usage
Defining Unit
from unitpy import U, Q, Unit, Quantity
# U = Unit
u = Unit("kilometer")
u = U("kilometer")
u = U("km")
u = U.kilometer
u = U.km
u = U("kilometer/hour")
u = U("km/h")
u = U.kilometer / U.hour
u = U.km / U.h
# properties
print(u.dimensionality) # [length] / [time]
print(u.dimensionless) # False
print(u.base_unit) # meter / second
Defining Quantity
** Quantity = Value + Unit **
from unitpy import U, Q , Unit, Quantity
# Q = Quantity
q = 1 * U("kilometer/hour")
q = 1 * (U.kilometer / U.hour)
q = Quantity("1 km/h")
q = Q("1 kilometer per hour")
q = Q("1*kilometer/hour")
# properties
print(q.unit) # kilometer / hour
print(q.dimensionality) # [length] / [time]
print(q.dimensionless) # False
print(q.base_unit) # meter / second
Unit Conversion
from unitpy import U, Q , Unit, Quantity
# Q = Quantity
q = 1 * U("km/h")
q2 = q.to("mile per hour")
print(q2) # 0.6213711922 mile / hour
Mathematical operation
from unitpy import U, Q
q = 1 * U("km/h")
q2 = 2.2 * U("mile per hour")
print(q2 + q) # 2.8213711923 mile / hour
print(q2 - q) # 1.5786288077 mile / hour
print(q2 * q) # 2.2 kilometer mile / hour**2
print(q2 / q) # 2.2 mile / kilometer
print((q2 / q).dimensionless) # True
Temperature
Abbreviations:
- fahrenheits: degF
- celsius: degC
- kelvin: degK, K
- rankine: degR
from unitpy import U, Q
q = 300 * U("K")
q2 = 200 * U("K")
print(q + q2) # 500.0 kelvin
print(q.to("degC")) # 26.85 Celsius
print(q.to("degF")) # 830.6344444444 Fahrenheit
print(q.to("degR")) # 166.6666666667 Rankine
Temperature units are non-multiplicative units. They are expressed with respect to a reference point (offset).
degC = 5/9 * (degF - 32)
Default behavior is absolute units.
For relative units use dedicated functions add_rel()
or sub_rel()
.
from unitpy import U, Q
q = 10 * U("degC")
q2 = 5 * U("degC")
# absolute
print(q.to("K")) # 283.15 kelvin
print(q + q2) # 288.15 Celsius
print((q + q2).to("K")) # 561.3 kelvin
print(q - q2) # -268.15 Celsius
print((q - q2).to("K")) # 5.0 kelvin
# relative
print(q.add_rel(q2)) # 15 Celsius
print(q.sub_rel(q2)) # 5 Celsius
print(abs(-10 * U.degC)) # 10 Celsius
Time
from unitpy import U
a = 1.234 * U.min
print(a) # 1.234 minute
b = a.to_timedelta()
print(b) # 0:01:14.040000
print(type(b)) # <class 'datetime.timedelta'>
Notes
- this package utilizes the American spellings "meter," "liter," and "ton"
- objects are support pickling
Project details
Release history Release notifications | RSS feed
Download files
Download the file for your platform. If you're not sure which to choose, learn more about installing packages.