[Tutor] Help in debugging some Python code.

[Danny Yoo]

> Traceback (most recent call last):
>   File "test.py", line 12, in ?
>     a=r.req()
>   File "/usr/local/lib/python2.2/site-packages/DNS/Base.py", line 148, in
> req
>     m.addQuestion(qname, qtype, DNS.Class.IN)
>   File "/usr/local/lib/python2.2/site-packages/DNS/Lib.py", line 427, in
> addQuestion
>     self.addname(qname)
>   File "/usr/local/lib/python2.2/site-packages/DNS/Lib.py", line 105, in
> addname
>     index.append(keys[j], offset + len(buf))
> TypeError: append() takes exactly one argument (2 given)
>
> Now I suspect that this utility was written for a previous version of
> Python, I'm using version 2.2 as you can see. I also suspect that the
> reported error is not the root of the problem but being inexperienced I
> don't know where to start looking for a solution. Any suggestions.

Hi Trevor,


My initial guess iwould be to change:

    index.append(keys[j], offset + len(buf))       ## Buggy

to:

    index.append((keys[j],
                  offset + len(buf)))              ## Better


The append() method was changed between an old release of Python and the
more recent versions: the old version implicitely inserted a tuple
collection if we gave append() more arguments, but this seemed somewhat
magical and was seen as a language defect for a while.

The recent version of Python requires us to explictely say that we're
inserting that tuple, which is what that extra set of parentheses does.


Hope this helps!