always the same object

Jeff Epler jepler at unpythonic.net
Wed Jan 21 00:50:36 CET 2004


If you included some code, maybe we'd be able to help you.

>>> struct.unpack("2i", " "*8)
(538976288, 538976288)

struct.unpack returned a tuple.  The tuple happens to be immutable, and
all the things it contains are immutable.  So there's no way to change
ever change the value of this object.  As far as I know, this would be
true for any struct format you care to choose.

(You could change the "value" of an immutable object if it contains some
mutable objects, like this:
	a = ([],)
	b = ([],)
	assert a == b
	a[0].append(0)
	assert a != b
a and b go from equal to unequal, even though a and b are both
immutable)

Jeff




More information about the Python-list mailing list