Delete dict and subdict items of some name

[Chris Angelico]

On Tue, Dec 18, 2012 at 8:33 AM, Mitya Sirenef <msirenef at lightbird.net> wrote:
> On 12/17/2012 01:30 PM, Tim Chase wrote:
>>
>> On 12/17/12 11:43, Mitya Sirenef wrote:
>>>
>>> On 12/17/2012 12:27 PM, Gnarlodious wrote:
>>>>
>>>> Hello. What I want to do is delete every dictionary key/value
>>>> of the name 'Favicon' regardless of depth in subdicts, of which
>>>> there are many. What is the best way to do it?
>>>
>>> Something like this should work:
>>>
>>> def delkey(d, key):
>>>       if isinstance(d, dict):
>>>           if key in d: del d[key]
>>>           for val in d.values():
>>>               delkey(val, key)
>>
>> Unless you have something hatefully recursive like
>>
>>    d = {}
>>    d["hello"] = d
>>
>> :-)
>
>
> True -- didn't think of that..!
>
> I guess then adding a check 'if val is not d: delkey(val, key)'
> would take care of it?

Nope, recursion could occur anywhere. You'd have to maintain a set of
"visited nodes" (or their id()s, same diff), and skip any that are in
it.

ChrisA