Op Friday 1 May 2015 06:42 CEST schreef Steven D'Aprano: > On Fri, 1 May 2015 02:06 am, Cecil Westerhof wrote: > >> If I execute: >> l = range(int(1E9) > > > Others have already answered your questions about memory. Let me > answer the question you didn't ask about style :-)
That can be very useful. > Don't use "l" as a variable name, as it looks too much like 1. > Better to use L, or even better, a meaningful name. > > Rather than convert a float 1E9 to an int at runtime, better to use > an int: > > range(10**9) > > > With recent versions of CPython, the compiler has a keyhole > optimiser which does constant folding. For implementations of Python > which don't do constant folding, 10**9 is likely to be faster than > int(1E9) -- but even if it isn't, does it matter? It will be very > fast one way of the other. The important thing is that 10**9 > expresses the intention to use an integer in a more direct fashion > than using 1E9. It was just a short hack to show the problem. In real code I would never use l. But I'll remember to use 10**9 instead of 1E9. -- Cecil Westerhof Senior Software Engineer LinkedIn: http://www.linkedin.com/in/cecilwesterhof -- https://mail.python.org/mailman/listinfo/python-list
