On 4/4/2012 7:32 PM, Chris Angelico wrote: > Don't know if it's what's meant on that page by the += operator,
Yes, it is. >> a=([1],) >> a[0].append(2) # This is fine [In the following, I use the term "name" rather loosely.] The append() method attempts to modify the object whose name is "a[0]". That object is a LIST, so the attempt succeeds. >> a[0]+=[3] # This is not. The assignment attempts to modify the object whose name is "a". That object is a TUPLE, so the attempt fails. This might be a surprise, but I'm not sure it deserves to be called a wart. Note the similarity to: temp = a[0] + [3] # succeeds a[0] = temp # fails -John -- http://mail.python.org/mailman/listinfo/python-list
