YAML general

Nico Schlömer | 12 Jun 2012 21:39

less verbose Python lib

Hi all,

in C++, typical YAML usage looks like

============ *snip* ============
YAML::Emitter out;
out << YAML::BeginSeq;
out << "eggs";
out << "bread";
out << "milk";
out << YAML::EndSeq;
============ *snap* ============

while the same thing in Python is (as far as I know)
============ *snip* ============
print yaml.emit([yaml.StreamStartEvent(),
                 yaml.DocumentStartEvent(),
                 yaml.SequenceStartEvent(anchor=None, tag=None, implicit=True),
                 yaml.ScalarEvent(anchor=None, tag=None,
implicit=(True, False), value=u'eggs'),
                 yaml.ScalarEvent(anchor=None, tag=None,
implicit=(True, False), value=u'bread'),
                 yaml.ScalarEvent(anchor=None, tag=None,
implicit=(True, False), value=u'milk'),
                 yaml.SequenceEndEvent()
               ])
============ *snap* ============

Is there any way to make this less verbose? (I don't even know why I
need all these options.)

(Continue reading)

headers

Dennis Lissov | 12 Jun 2012 22:52

Re: less verbose Python lib

Hello Nico,

in Python YAML is typically mapped directly to the trees of objects.
The YAML sequence is mapped to the Python list, so using

    yaml.dump(['eggs', 'bread', 'milk'], default_flow_style=False)

and if the equivalent output of '[eggs, bread, milk]' is acceptable,
the keyword argument may also be omitted. Unless you need to
explicitly deal with the representation and serialization steps, it's
the easiest way to deal with YAML in Python.

Good luck,
Dennis.

On Tue, Jun 12, 2012 at 11:39 PM, Nico Schlömer
<nico.schloemer <at> gmail.com> wrote:
> Hi all,
>
> in C++, typical YAML usage looks like
>
> ============ *snip* ============
> YAML::Emitter out;
> out << YAML::BeginSeq;
> out << "eggs";
> out << "bread";
> out << "milk";
> out << YAML::EndSeq;
> ============ *snap* ============
>

(Continue reading)

headers

Nico Schlömer | 12 Jun 2012 23:01

Re: less verbose Python lib

Compiling the list is difficult for me as the items take a long time
to be computed (the emitter is supposed to be part of a numerical
code), so I wouldn't want to have to wait for the last item to arrive
until they're printed all together.

On Tue, Jun 12, 2012 at 10:52 PM, Dennis Lissov
<dennis.lissov@...> wrote:
> Hello Nico,
>
> in Python YAML is typically mapped directly to the trees of objects.
> The YAML sequence is mapped to the Python list, so using
>
>    yaml.dump(['eggs', 'bread', 'milk'], default_flow_style=False)
>
> and if the equivalent output of '[eggs, bread, milk]' is acceptable,
> the keyword argument may also be omitted. Unless you need to
> explicitly deal with the representation and serialization steps, it's
> the easiest way to deal with YAML in Python.
>
> Good luck,
> Dennis.
>
> On Tue, Jun 12, 2012 at 11:39 PM, Nico Schlömer
> <nico.schloemer@...> wrote:
>> Hi all,
>>
>> in C++, typical YAML usage looks like
>>
>> ============ *snip* ============
>> YAML::Emitter out;

(Continue reading)

headers

Daniel Goertzen | 12 Jun 2012 23:18

Re: less verbose Python lib

Perhaps implement your items as a generator instead of building the whole list ahead of time.

Dan.

On Tue, Jun 12, 2012 at 4:01 PM, Nico Schlömer <nico.schloemer <at> gmail.com> wrote:

Compiling the list is difficult for me as the items take a long time
to be computed (the emitter is supposed to be part of a numerical
code), so I wouldn't want to have to wait for the last item to arrive
until they're printed all together.

On Tue, Jun 12, 2012 at 10:52 PM, Dennis Lissov <dennis.lissov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> Hello Nico,
>
> in Python YAML is typically mapped directly to the trees of objects.
> The YAML sequence is mapped to the Python list, so using
>
> yaml.dump(['eggs', 'bread', 'milk'], default_flow_style=False)
>
> and if the equivalent output of '[eggs, bread, milk]' is acceptable,
> the keyword argument may also be omitted. Unless you need to
> explicitly deal with the representation and serialization steps, it's
> the easiest way to deal with YAML in Python.
>
> Good luck,
> Dennis.
>
> On Tue, Jun 12, 2012 at 11:39 PM, Nico Schlömer
> <nico.schloemer <at> gmail.com> wrote:
>> Hi all,
>>
>> in C++, typical YAML usage looks like
>>
>> ============ *snip* ============
>> YAML::Emitter out;
>> out << YAML::BeginSeq;
>> out << "eggs";
>> out << "bread";
>> out << "milk";
>> out << YAML::EndSeq;
>> ============ *snap* ============
>>
>> while the same thing in Python is (as far as I know)
>> ============ *snip* ============
>> print yaml.emit([yaml.StreamStartEvent(),
>> yaml.DocumentStartEvent(),
>> yaml.SequenceStartEvent(anchor=None, tag=None, implicit=True),
>> yaml.ScalarEvent(anchor=None, tag=None,
>> implicit=(True, False), value=u'eggs'),
>> yaml.ScalarEvent(anchor=None, tag=None,
>> implicit=(True, False), value=u'bread'),
>> yaml.ScalarEvent(anchor=None, tag=None,
>> implicit=(True, False), value=u'milk'),
>> yaml.SequenceEndEvent()
>> ])
>> ============ *snap* ============
>>
>> Is there any way to make this less verbose? (I don't even know why I
>> need all these options.)
>>
>> Cheers,
>> Nico
>>
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Exclusive live event will cover all the ways today's security and 
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