pint 0.4

Design principles

Although there are already a few very good Python packages to handle physical quantities, no one was really fitting my needs. Like most developers, I programed Pint to scratch my own itches.

• Unit parsing: prefixed and pluralized forms of units are recognized without explicitly defining them. In other words: as the prefix kilo and the unit meter are defined, Pint understands kilometers. This results in a much shorter and maintainable unit definition list as compared to other packages.

• Standalone unit definitions: units definitions are loaded from simple and easy to edit text file. Adding and changing units and their definitions does not involve changing the code.

• Advanced string formatting: a quantity can be formatted into string using PEP 3101 syntax. Extended conversion flags are given to provide latex and pretty formatting.

• Small codebase: small and easy to maintain with a flat hierarchy.

• Dependency free: it depends only on Python and it’s standard library.

• Python 2 and 3: A single codebase that runs unchanged in Python 2.7+ and Python 3.0+.

• Advanced NumPy support: While NumPy is not a requirement for Pint, when available ndarray methods and ufuncs can be used in Quantity objects.

Pint is written and maintained by Hernan E. Grecco <hernan.grecco@gmail.com>.

Other contributors, listed alphabetically, are:

• Richard Barnes <rbarnes@umn.edu>

• Alexander Böhn <fish2000@gmail.com>

• Dave Brooks <dave@bcs.co.nz>

• Giel van Schijndel <me@mortis.eu>

• Daniel Sokolowski <moc.buhtig@danols.com>

• Brend Wanders <b.wanders@utwente.nl>

0.4 (2013-12-17)

• Introduced Contexts: relation between incompatible dimensions. (Issue #65)

• Fixed get_base_units for non multiplicative units. (Related to issue #66)

• Implemented default formatting for quantities.

• Changed comparison between Quantities containing NumPy arrays. (Issue #75) - BACKWARDS INCOMPATIBLE CHANGE

• Fixes for NumPy 1.8 due to changes in handling binary ops. (Issue #73)

0.3.3 (2013-11-29)

• ParseHelper can now parse units named like python keywords. (Issue #69)

• Fix comparison of quantities. (Issue #74)

• Fix Inequality operator. (Issue #70, thanks muggenhor)

• Improved travis configuration. (thanks muggenhor)

0.3.2 (2013-10-22)

• Fix get_dimensionality for non multiplicative units. (Issue #66)

• Proper handling of @import directive inside a file read using pkg_resources. (Issue #68)

0.3.1 (2013-09-15)

• fix right division on python 2.7 (Issue #58, thanks natezb)

• fix formatting of fractional exponentials between 0 and 1. (Issue #62, thanks jdreaver)

• fix installation as egg. (Issue #61)

• fix handling of strange values as input of Quantity. (Issue #53)

• math operations between quantities of different registries now raise a ValueError. (Issue #52)

0.3 (2013-09-02)

• support for IPython autocomplete and rich display. (Issues #30 and #31)

• support for @import directive in definitions file. (Issue #22)

• support for wrapping functions to make them pint-aware. (Issue #16)

• support for comparing UnitsContainer to string. (Issue #35)

• fix error raised while converting from a single unit to one expressed as the relation between many. (Issue #29)

• fix error raised when unit symbol is missing. (Issue #41)

• fix error raised when magnitude is Decimal. (Issue #46, thanks danielsokolowski)

• support for non-installed pint. (Issue #42, thanks danielsokolowski)

• support for application of numpy function on non-ndarray magnitudes. (Issue #44)

• support for math operations on dimensionless Quantities (written with units). (Issue #45)

• fix obtaining dimensionless quantity from string. (Issue #50)

• fix adding and comparing numbers to a dimensionless quantity (written with units). (Issue #54)

• Support for iter in Quantity. (Issue #55, thanks natezb)

0.2.1 (2013-07-02)

• fix error raised while converting from a single unit to one expressed as the relation between many. (Issue #29)

0.2 (2013-05-13)

• support for Measurement (Quantity +/- error).

• implemented buckingham pi theorem for dimensional analysis.

• support for temperature units and temperature difference units.

• parser can infers if the user mean temperature or temperature difference.

• support for derived dimensions (e.g. [speed] = [length] / [time]).

• refactored the code into multiple files.

• refactored code to isolate definitions and converters.

• refactored formatter out of UnitParser class.

• added tox and travis config files for CI.

• comprehensive NumPy testing including almost all ufuncs.

• full NumPy support (features is not longer experimental).

• fixed bug preventing from having independent registries. (Issue #10, thanks bwanders)

• forces real division as default for Quantities. (Issue #7, thanks dbrnz)

• improved default unit definition file. (Issue #13, thanks r-barnes)

• smarter parser supporting spaces as multiplications and other nice features. (Issue #13, thanks r-barnes)

• moved testsuite inside package.

• short forms of binary prefixes, more units and fix to less than comparison. (Issue #20, thanks muggenhor)

• pint is now zip-safe (Issue #23, thanks muggenhor)

Version 0.1.3 (2013-01-07)

• abbreviated quantity string formating.

• complete Python 2.7 compatibility.

• implemented pickle support for Quantities objects.

• extended NumPy support.

• various bugfixes.

Version 0.1.2 (2012-08-12)

• experimenal NumPy support.

• included default unit definitions file. (Issue #1, thanks fish2000)

• better testing.

• various bugfixes.

• fixed some units definitions. (Issue #4, thanks craigholm)

Version 0.1.1 (2012-07-31)

• better packaging and installation.

Version 0.1 (2012-07-26)

• first public release.