Tobias C. Rittweiler schrieb: > Hi! > > Has anyone added special syntax to allow writing numeric literals with > physical units? So you can write 12m + 34cm, and would get 12.34m. > > My question is how would you modify the BNF the most sensible way to > allow for this? The above example is simple, but think of 42 km/h. > > (For my purposes, modifying the BNF is perfectly reasonable, but if you > can depict a good, and convenient!, way that would not result in > modifying it, I'd like to hear it, too.)
Hi, normally you wouldn't add units to the language itself. When using them programmatically, it should be no effort to use a class that represents a quantity with unit. This can be made as easy as making "m" an object of that type, so that you only need to type "2*m" to get two meters. For the interactive shell, using a wrapper that allows simplified input is also a possibility, like IPython's "-profile physics" mode, or something like http://bitbucket.org/birkenfeld/phsh/ which allows you to write >>> `1 m` + `12 cm` 1.12 m cheers, Georg _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
