pint 0.5.2

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 its 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:

• Alexander Böhn <fish2000@gmail.com>

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

• choloepus

• coutinho <coutinho@esrf.fr>

• Daniel Sokolowski <daniel.sokolowski@danols.com>

• Dave Brooks <dave@bcs.co.nz>

• Eduard Bopp <eduard.bopp@aepsil0n.de>

• Felix Hummel <felix@felixhummel.de>

• Giel van Schijndel <me@mortis.eu>

• James Rowe <jnrowe@gmail.com>

• Jim Turner <jturner314@gmail.com>

• Joel B. Mohler <joel@kiwistrawberry.us>

• John David Reaver <jdreaver@adlerhorst.com>

• Kenneth D. Mankoff <mankoff@gmail.com>

• Luke Campbell <luke.s.campbell@gmail.com>

• Nate Bogdanowicz <natezb@gmail.com>

• Peter Grayson <jpgrayson@gmail.com>

• Richard Barnes <rbarnes@umn.edu>

• Sundar Raman <cybertoast@gmail.com>

• Tiago Coutinho <coutinho@esrf.fr>

• Tom Ritchford <tom@swirly.com>

0.5.2 (2014-07-31)

• Changed travis config to use miniconda for faster testing.

• Added wheel configuration to setup.cfg.

• Ensure resource streams are closed after reading.

• Require setuptools. (Issue #169)

• Implemented real, imag and T Quantity properties. (Issue #171)

• Implemented __int__ and __long__ for Quantity (Issue #170)

• Fixed SI prefix error on ureg.convert. (Issue #156, thanks jdreaver)

• Fixed parsing of multiparemeter contexts. (Issue #174)

0.5.1 (2014-06-03)

• Implemented a standard way to change the registry used in unpickling operations. (Issue #148)

• Fix bug where conversion would fail due to caching. (Issue #140, thanks jdreaver)

• Allow assigning Not a Number to a quantity array. (Issue #127)

• Decoupled Quantity in place and not in place unit conversion methods.

• Return None in functions that modify quantities in place.

• Improved testing infrastructure to check for unwanted warnings.

• Added test function at the package level to run all tests.

0.5 (2014-05-07)

• Improved test suite helper functions.

• Print honors default format w/o format(). (Issue #132, thanks mankoff)

• Fixed sum() by treating number zero as a special case. (Issue #122, thanks rec)

• Improved behaviour in ScaleConverter, OffsetConverter and Quantity.to. (Issue #120)

• Reimplemented loading of default definitions to allow Pint in a cx_freeze or similar package. (Issue #118, thanks jbmohler)

• Implemented parsing of pretty printed units. (Issue #117, thanks jpgrayson)

• Fixed representation of dimensionless quantities. (Issue #112, thanks rec)

• Raise error when invalid formatting code is given. (Issue #111, thanks rec)

• Default registry to lazy load, raise error on redefinition (Issue #108, thanks rec, aepsil0n)

• Added condensed format. (Issue #107, thanks rec)

• Added UnitRegistry () operator to parse expression replacing []. (Issue #106, thanks rec)

• Optional case insensitive unit parsing. (Issue #105, thanks rec, jeremyfreeman, dbrnz)

• Change the Quantity mutability depending on magnitude type. (Issue #104, thanks rec)

• Implemented API to list compatible units. (Issue #89)

• Implemented cache of key UnitRegistry methods.

• Rewrote the Measurement class to use uncertainties. (Issue #24)

0.4.2 (2014-02-14)

• Python 2.6 support (Issue #96, thanks tiagocoutinho)

• Fixed symbol for inch. (Issue #102, thanks cybertoast)

• Stop raising AttributeError when wrapping funcs without all of the attributes. (Issue #100, thanks jturner314)

• Fixed warning appearing in Py2.x when comparing a Numpy Array with an empty string. (Issue #98, thanks jturner314)

• Add links to AUR packages in docs. (Issue #91, thanks jturner314)

• Fixed garbage collection related problem. (Issue #92, thanks jturner314)

0.4.1 (2014-01-12)

• Integer Division with Arrays. (Issue #80, thanks jdreaver)

• Improved Documentation. (Issue #83, thanks choloepus)

• Removed ‘h’ alias for hour due to conflict with Planck’s constant. (Issue #82, thanks choloepus)

• Improved get_base_units for non-multiplicative units. (Issue #85, thanks exxus)

• Refactored code for multiplication. (Issue #84, thanks jturner314)

• Removed ‘R’ alias for roentgen as it collides with molar_gas_constant. (Issue #87, thanks rsking84)

• Improved naming of temperature units and multiplication of non-multiplicative units. (Issue #86, tahsnk exxus)

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.