Comment #6 on issue 1717 by nicolas.pourcelot: inconsistency between facts http://code.google.com/p/sympy/issues/detail?id=1717
"BTW, 'not is None' is more efficient than '!= None'." I think you mean 'is not None'. "How is "not is None" faster than "!= None"? This is interesting to me." As far as I know, if you use 'A is B' or 'A is not B', Python will simply compare A and B memory address. But if you use 'A == B' or 'A != B', Python will first check if A or B have special comparison methods .__eq__() or .__ne__(), and if not, use memory address comparison. So, that's a bit slower. -- You received this message because you are listed in the owner or CC fields of this issue, or because you starred this issue. You may adjust your issue notification preferences at: http://code.google.com/hosting/settings -- You received this message because you are subscribed to the Google Groups "sympy-issues" group. To post to this group, send email to sympy-iss...@googlegroups.com. To unsubscribe from this group, send email to sympy-issues+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sympy-issues?hl=en.
