I apologize if this has been answered before or if it is easy to find in the docs. (I couldn't find it but might have missed it)
I'm trying to understand the differences between namespaces in class definitions vs. function definitions. Consider this function: >>> def a(): ... foo = 'foo' ... def g(x): ... return foo ... print g(1) ... >>> a() foo >>> Now, I replace the first "def" with "class": >>> class a(): ... foo = 'foo' ... def g(x): ... return foo ... print g(1) ... Traceback (most recent call last): File "<stdin>", line 1, in <module> File "<stdin>", line 5, in a File "<stdin>", line 4, in g NameError: global name 'foo' is not defined So, the variable "foo" is not available inside the function inside class as it is inside the (inner) function. I figured this was just because the class was still being defined, so I tried this: >>> class a(): ... foo = 'foo' ... def g(x): ... return foo ... >>> x = a() >>> x.g() Traceback (most recent call last): File "<stdin>", line 1, in <module> File "<stdin>", line 4, in g NameError: global name 'foo' is not defined >>> which still fails. I had expected that "foo" would be available within the namespace of the object instance. I was wrong. For my final attempt, I add the prefix "a." to my use of "foo" >>> class a(): ... foo = 'foo' ... def g(x): ... return a.foo ... >>> x = a() >>> x.g() 'foo' So, this works and I can use it. However, I would like a deeper understanding of why I cannot use "foo" as an unqualified variable inside the method in the class. If Python allowed such a thing, what problems would that cause? -- Gerald Britton -- http://mail.python.org/mailman/listinfo/python-list
