Michael Torrie於 2013年6月20日星期四UTC+8下午2時01分11秒寫道: > > But since the LISP never really got a form beyond S-expressions, > > leaving us with lots of parenthesis everywhere, Python wins much as the > > Hitchhiker's Guide to the Galaxy wins.
Yep, a list is mutable even it's empty. But constant integers, floats, strings, and None is immutable. The variables in a function of python with default parameters which could be mutable or immutable. def fun1( x, alist=[]): alist.append(x*x) return alist ## valid def fun2(x, alist=None): if alist==None: alist=[] alist.append(x*x) return alist # kind of boring to show the name binding mechanism of objects # in Python in different usages -- http://mail.python.org/mailman/listinfo/python-list