In message <mailman.504.1288718704.2218.python-l...@python.org>, Robert Kern wrote:
> On 11/2/10 2:12 AM, Lawrence D'Oliveiro wrote: > >> In message<mailman.475.1288670833.2218.python-l...@python.org>, Robert >> Kern wrote: >> >>> "Immutable objects" are just those without an obvious API for modifying >>> them. >> >> They are ones with NO legal language constructs for modifying them. Hint: >> if a selector of some part of such an object were to occur on the LHS of >> an assignment, and that would raise an error, then the object is >> immutable. The interpreter already knows all this. > > Incorrect. RHS method calls can often modify objects. So bloody what? > Show me the algorithm that the interpreter can use to determine whether or > not an object is mutable. Go look in the code for the one it already uses in places where immutable objects are currently required. >>> With various trickeries, I can mutate any immutable object. >> >> None within the Python language itself. Which is what we’re talking about >> here: a language construct which is probably one of the top 3 sources of >> grief to Python newbies. And not-so-newbies. > > "import ctypes" is within the Python language. And in the old BASIC days, we had “PEEK” and “POKE”. So by your reasoning, that invalidated the language rules, too. -- http://mail.python.org/mailman/listinfo/python-list
