Portable readable dump format

[Chris Stiles]

Is there a human readable dump format for objects ? As opposed to pickling ?
It doesn't necessarily have to be XML - in fact i'd prefer if it wasn't ;) -
but ISTR an XML dump library.

--
regards, chris

[Donald 'Paddy' McCarthy]

Re: Portable readable dump format



Chris Stiles wrote:[color=blue]
> Is there a human readable dump format for objects ? As opposed to pickling ?
> It doesn't necessarily have to be XML - in fact i'd prefer if it wasn't ;) -
> but ISTR an XML dump library.
>[/color]

There is YAML http://yaml.org/

and http://python.yaml.org/, http://yaml.freepan.org/index.cgi?LibSyck

[Chris Stiles]

Re: Portable readable dump format

Donald 'Paddy' McCarthy <paddy3118@nets cape.netNOTthis BIT> writes:[color=blue]
> There is YAML http://yaml.org/
>
> and http://python.yaml.org/, http://yaml.freepan.org/index.cgi?LibSyck[/color]

Thank you. That was exactly the library I was after.

--
regards, chris

[David Mertz]

Re: Portable readable dump format

Chris Stiles <chris@example. org> wrote previously:
|Is there a human readable dump format for objects ? As opposed to
|pickling ? It doesn't necessarily have to be XML - in fact i'd prefer
|if it wasn't ;) - but ISTR an XML dump library.

Another poster pointed to YAML, which is a good format. If you want
XML, however, I have gnosis.xml.pick le in Gnosis Utilities.

Some comparisons:
[color=blue][color=green][color=darkred]
>>> import gnosis.xml.pick le
>>> import yaml
>>> class Something:[/color][/color][/color]
... def __init__(self):
... self.tup = (1,2,3)
... self.dct = {1.4:5.6,7.8:9. 0}
... self.str = "Spam and eggs"
...[color=blue][color=green][color=darkred]
>>> o = Something()
>>> print gnosis.xml.pick le.dumps(o)[/color][/color][/color]
<?xml version="1.0"?>
<!DOCTYPE PyObject SYSTEM "PyObjects.dtd" >
<PyObject module="__main_ _" class="Somethin g" id="2283692">
<attr name="tup" type="tuple" id="2577828" >
<item type="numeric" value="1" />
<item type="numeric" value="2" />
<item type="numeric" value="3" />
</attr>
<attr name="dct" type="dict" id="2829140" >
<entry>
<key type="numeric" value="1.399999 9999999999" />
<val type="numeric" value="5.599999 9999999996" />
</entry>
<entry>
<key type="numeric" value="7.799999 9999999998" />
<val type="numeric" value="9." />
</entry>
</attr>
<attr name="str" type="string" value="Spam and eggs" />
</PyObject>[color=blue][color=green][color=darkred]
>>> print yaml.dump(o)[/color][/color][/color]
--- !!__main__.Some thing
dct:
1.4: 5.6
7.8: 9.0
str: Spam and eggs
tup:
- 1
- 2
- 3

Certainly YAML is a lot less verbose (but also in a way less explicit).
The method 'yaml.dump()' is misnamed, however, it should have an 's' at
the end.

However, notice this:
[color=blue][color=green][color=darkred]
>>> class NewSomething(ob ject):[/color][/color][/color]
... def __init__(self):
... self.tup = (1,2,3)
... self.dct = {1.4:5.6,7.8:9. 0}
... self.str = "Spam and eggs"
...[color=blue][color=green][color=darkred]
>>> o2 = NewSomething()
>>> print yaml.dump(o2)[/color][/color][/color]
--- <__main__.NewSo mething object at 0x2abbcc>

Gnosis does fine here:
[color=blue][color=green][color=darkred]
>>> print gnosis.xml.pick le.dumps(o2)[/color][/color][/color]
<?xml version="1.0"?>
<!DOCTYPE PyObject SYSTEM "PyObjects.dtd" >
<PyObject module="__main_ _" class="NewSomet hing" id="2800588">
<attr name="tup" type="tuple" id="2576628" >
<item type="numeric" value="1" />
<item type="numeric" value="2" />
<item type="numeric" value="3" />
</attr>
<attr name="dct" type="dict" id="2829820" >
<entry>
<key type="numeric" value="1.399999 9999999999" />
<val type="numeric" value="5.599999 9999999996" />
</entry>
<entry>
<key type="numeric" value="7.799999 9999999998" />
<val type="numeric" value="9." />
</entry>
</attr>
<attr name="str" type="string" value="Spam and eggs" />
</PyObject>

Moreover, notice this:
[color=blue][color=green][color=darkred]
>>> class ListandTuple:[/color][/color][/color]
... def __init__(self):
... self.tup = (1,2,3)
... self.lst = [1,2,3]
...[color=blue][color=green][color=darkred]
>>> lt = ListandTuple()
>>> print yaml.dump(lt)[/color][/color][/color]
--- !!__main__.List andTuple
lst:
- 1
- 2
- 3
tup:
- 1
- 2
- 3

YAML is lossy in regard to Python types. Some other languages supported
by the YAML format do not have the list/tuple distinction, but since
Python does, usually you want to keep it (which gnosis.xml.pick le does).

Yours, David...

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