>There are thousands of units in use in sciences, commerce, engineering, >ordinary life, etc. In all of them, it is not uncommon for the same few >letters to represent multiple things, depending on context.
Units in science and engineering are NOT AT ALL ambiguous. If they were, planes would be crashing every day. If we consider distinct sets of units, such as SI, there are guaranteed to not be any collisions in notation. Even English/Imperial and SI units do not conflict as far as I know. Commerce (finance?) is another story, so yes, there needs be groupings (i.e. - namespaces) of such things. > An electron volt is a unit of energy. Or of mass. Or of momentum. An electron volt is a unit of energy and only a unit of energy. Knowing a particle's energy (in certain situations) means that you also know other physical quantities about that object, and so in casual conversation (and the occasional poorly reviewed journal article) you find them used interchangeably. But that does not mean that an electron volt is a unit of mass. It just isn't. These units are set by standards. Standards do not leave any room for ambiguity. The only context needed is what standard applies. And there are LOTS of people who are familiar with these standards who could be called upon to lend a hand. > I'm older than 35 (Earth) years, but my age is also counted differently > according to different calendars and cultural conventions. Of his > examples, °F is the only one that is completely convertible to other > temperature scales, but even there, it's rare to see a bread recipe in > degrees Kelvin. Dates and years are not standard units of time. The only SI unit of time is the "s" (second). The `datetime` object today is composed of unitless primitives and would continue to be so. The value returned by time.time() could remain unitless, or it could have a unit of seconds. Either one would make sense. So this is also not a problem. > Units like time intervals and currencies are EXCEEDINGLY complicated. The > conversion rate between Dirham and USD fluctuates by microsecond, but can > also have two simultaneous values on different exchanges. At the least, a > unit of currency has built into it an absolute time, but also often a > relative time to a specific refence time. Would it help if we stopped saying "units" and instead referred to "standard units"? _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/RYCU4FQJ2NLG22BL26MBVVE7SECUB5QK/ Code of Conduct: http://python.org/psf/codeofconduct/
