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Re: [Configobj-develop] has_section function?
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From: Michael F. <fuz...@vo...> - 2011-10-28 14:18:21
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On 28/10/2011 15:08, David Hostetler wrote:
> Hey Michael,
>
> Unless I'm mistaken, your suggestions don't completely address Thomas'
> question.
>
> configfile.sections and configfile.scalars don't expose nested
> entries. So yes, he can use those, but they'll be misleading unless
> he's using configuration data that he can guarantee isn't nested, in
> which case he's not any better off than when he was using ConfigParser.
>
Well he is because you can't have nested sections *at all* with
ConfigParser (and there are lots of other reasons to prefer ConfigObj...).
> I *think* that he was hoping there was some super-convenient way to
> ask a ConfigObj instance to be deeply introspective and test for a
> given section-name/key-name anywhere in the cfg hierarchy.
>
> Not terribly difficult to do with a smidge of recursion, but not
> natively offered by the ConfigObj interface as far as I know.
The code I suggested was an exact equivalent of "has_section" and
"has_option" in ConfigParser - but you're right, this code only checks
the current section and doesn't recurse. You could write a recursive
version easily, but what would that be useful for? Knowing that
*somewhere* inside a nested data structure the section/option exists
isn't useful, because you still have to write the recursive code to find
it. By the time you've done that you've written the code to check as well...
(It may be useful for configfile of *known* structure - but in that case
you can just go to the section that should contain the option /
sub-section and use the code I suggested.)
That aside, recursively checking sections is easy, here's an example
that can be modified based on the exact use case required:
def contains_entry(section, entry):
if entry in section:
return True
for sub in section.sections:
if contains_entry(section[sub], entry):
return True
You call it with:
contains_entry(configfile, 'some_key')
All the best,
Michael Foord
>
>
> cheers,
>
> -hoss
>
> David Hostetler
> neg...@gm... <mailto:neg...@gm...>
>
>
>
> On Thu, Oct 27, 2011 at 19:51, Michael Foord
> <fuz...@vo... <mailto:fuz...@vo...>> wrote:
>
> Hello Thomas,
>
> Your email isn't spam, it's entirely on topic!
>
> ConfigObj doesn't have those methods specifically - *however* the
> information is easy to find out.
>
> The following tells you if an entry is in a ConfigObj instance
> (but not whether it is a section or a value):
>
> 'foo' in configfile
>
> For just checking for the presence of a section you can do:
>
> 'foo' in configfile.sections
>
> For values you can do:
>
> 'foo' in configfile.scalars
>
> That code works on individual sections as well as the main
> ConfigObj instance.
>
> You could also do:
>
> result = configfile.get('foo')
> if result is None:
> # entry is not present
> elif isinstance(result, dict):
> # entry is present and a section
> else:
> # entry is present and a value
>
> All the best,
>
> Michael Foord
>
>
> On 26/10/2011 23:03, Thomas Sturges-Allard wrote:
>> Sorry to spam, but i'm guessing this can be answered easily.
>>
>> Was really glad to discover the configobj module as I had
>> previously been restricted by ConfigParser.
>>
>> The only important feature I have yet to find is an equivalent of
>> " configfile.has_section('Blah') " and " configfile.has_option
>> ('Section1', 'Option1') " which are listed here:
>> http://docs.python.org/library/configparser.html?highlight=config%20parser#configparser-objects
>> . Do such things exist?
>>
>> I guess I could use ConfigParser as well just for this feature
>> but it would not support nested sections. I had a fiddle with
>> exceptions in classes as a way of making a feature myself but I
>> can't seem to get it to work for KeyError exceptions (i.e. they
>> crash the interpreter anyway). The validation system is not
>> practical in this instance as what will be checked and what it
>> will be checked for is reasonably dynamic.
>>
>> I am using Python 2.72 and configobj 7.72 on Windows XP with
>> Notepad ++
>>
>> Thanks!
>>
>> Thomas Sturges-Allard
>> http://zig13.termisoc.org
>>
>>
>> ------------------------------------------------------------------------------
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>>
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>
>
> --
> http://www.voidspace.org.uk/
>
> May you do good and not evil
> May you find forgiveness for yourself and forgive others
> May you share freely, never taking more than you give.
> -- the sqlite blessinghttp://www.sqlite.org/different.html
>
>
> ------------------------------------------------------------------------------
> The demand for IT networking professionals continues to grow, and the
> demand for specialized networking skills is growing even more rapidly.
> Take a complimentary Learning@Cisco Self-Assessment and learn
> about Cisco certifications, training, and career opportunities.
> http://p.sf.net/sfu/cisco-dev2dev
> _______________________________________________
> Configobj-develop mailing list
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> <mailto:Con...@li...>
> https://lists.sourceforge.net/lists/listinfo/configobj-develop
>
>
>
>
> ------------------------------------------------------------------------------
> The demand for IT networking professionals continues to grow, and the
> demand for specialized networking skills is growing even more rapidly.
> Take a complimentary Learning@Cisco Self-Assessment and learn
> about Cisco certifications, training, and career opportunities.
> http://p.sf.net/sfu/cisco-dev2dev
>
>
> _______________________________________________
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--
http://www.voidspace.org.uk/
May you do good and not evil
May you find forgiveness for yourself and forgive others
May you share freely, never taking more than you give.
-- the sqlite blessing http://www.sqlite.org/different.html
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