The udunits2 module

Note

This module is not maintaned. Use https://github.com/hgrecco/pint/ or https://github.com/SciTools/cf-units/ instead.

Creating and manipulating units

First, import the module:

>>> from udunits2 import *

Before a unit can be created one needs to create a unit system:

>>> sys = System()

The constructor also takes a path to an XML file with a unit database.

Now we're ready to create some units.

>>> kg = Unit(sys, "kg")
>>> m = Unit(sys, "meter")
>>> s = Unit(sys, "second")
>>> kg / m**2 / s
<units of 'm-2.kg.s-1'>

Converting data

The Converter class is used to convert data between different units

>>> converter = Converter((Unit(sys, "Celsius"), Unit(sys, "Fahrenheit")))
>>> converter
<unit converter 'y = 1.8*x + 32'>
>>> converter(0.0)
31.999999999999886

It is also possible to process NumPy arrays (float32 and float64), as well as anything numpy.asarray can process.

>>> from numpy import zeros
>>> a = zeros((3,3), dtype=np.int) + 10
>>> converter(a)
array([[ 50.,  50.,  50.],
       [ 50.,  50.,  50.],
       [ 50.,  50.,  50.]])

>>> converter([0, 10, 20, 30])
array([ 32.,  50.,  68.,  86.])

Testing this module

You can check if this module does what is promised above by running

python -m doctest -v README.rst