PEP 8 says, "Comparisons to singletons like None should always be done with 'is' or 'is not', never the equality operators." I know that "is" is an identity operator, "==" and "!=" are the equality operators, but I'm not sure what other singletons are being referred to here.
Also, I've seen code that does things like: if foo is 3: if foo is not '': Are these valid uses of "is"? Thanks in advance. -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
