Consider the following code: 0 = 42 print 0
If you write it into sage's ipython, it of course gives you an error. More precisely, you get ValueError: The name "0" is not a valid Python identifier. But suppose you write it into a file bug.sage, and execute it using sage bug.sage, you get 42! The explanation is actually pretty simple: when you execute sage bug.sage, bug.sage is preparsed to bug.sage.py which is the following: # This file was *autogenerated* from the file bug.sage from sage.all_cmdline import * # import sage library _sage_const_42 = Integer(42); _sage_const_0 = Integer(0) _sage_const_0 = _sage_const_42 print _sage_const_0 Since 0 is replaced by _sage_const_0, you can affect any value to it. Is this a known bug? Is there a way in Python to declare that _sage_const_i is immutable? I wanted to open a ticket, but as noticed by Dima, trac seems to be down... Bruno -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
