Raymond Hettinger a écrit : > Gustav Hållberg wrote: > >>I tried finding a discussion around adding the possibility to have >>optional underscores inside numbers in Python. This is a popular option >>available in several "competing" scripting langauges, that I would love >>to see in Python. >> >>Examples: >> 1_234_567 >> 0xdead_beef >> 3.141_592 > > > I suppose it could be done. OTOH, one could argue that most production > code has no business hardwiring-in numerical constants greater than 999 > ;-) > That's what I thought at first, but Steven D'Aprano made some good points here IMHO, ie :
""" Not all numeric constants used have simple formulae, or *any* formulae, or can be calculated on the fly in any reasonable time. Numeric programming often uses magic constants which truly are "magic" (in the sense that where they come from requires deep, difficult, and sometimes hidden knowledge). Nobody sensible wants to be typing in long strings of digits, but sometimes it is unavoidable. """ and """ Another sensible usage case is in the interactive interpreter. If you are using Python interactively, you may wish to use numeric literals with large numbers of digits. It is not feasible to read them from a data file, and using a special converter function is impractical and unnecessary. """ So even if it's far from a common use case for *most* Python users, it may be a common use case for *some* Python users. Also, someone mentionned the use of Python as a configuration langage - which is probably a much more common use case. So FWIW, I'd be +1 on adding it *if and only if*: - it's trivial to implement [1] - it doesn't break older code and +1 on the space as group delimiter BTW. [1]: I never wrote a language by myself, but I've played a bit with parsers and lexers, and I _guess_ (which implies I may be wrong !-) it wouldn't require much work to add support for a "literal numeric grouping" syntax in Python. -- http://mail.python.org/mailman/listinfo/python-list
