On Fri, 12 Jul 2019, Riccardo (Jack) Lucchetti wrote:
> On Fri, 12 Jul 2019, Allin Cottrell wrote:
>
> > On Fri, 12 Jul 2019, Sven Schreiber wrote:
> >
> > > Something else: BTW, the guide mentions that --send-data is not
> > > available with Ox, but is silent for the Python case. Actually Artur and
> > > I are working (not too hard) on more tools for passing stuff to Python,
> > > but enabling --send-data would also be nice. What Python/numpy functions
> > > would you need to make this work?
> >
> > Basically just a CSV reading function -- and presumably a target
> > structure that handles variable names, to make a distinction with just
> > sending data in matrix form.
>
> In fact, I was thinking about this some time ago: our --send-data apparatus
> goes back to a time when we didn't have all the data types we have now,
> particularly bundles. It would be really cool if we could pass bundles to
> languages that support some variant of associative arrays, eg R, where they
> call them lists, or Python, where they call them dicrtionaries (IIRC). That
> would give us enormnous flexibility. Of course, (a) we'd have to write
> import-export functions for those languages and (b) we'dd introduce some
> dependencies in the target languages, but I reckon that, given the mechanism
> we have for serialising a bundle as an xml file, that would be doable.
>
> Proof-of-concept:
>
> <hansl>
> bwrite(defbundle("x", 42, "s", "foo"), "b.xml")
>
> foreign language=R
> library(XML);
> b = xmlToList(xmlParse("b.xml"));
> l <- length(b);
> for (i in (1:l)) {
> type <- b[[i]]$.attrs["type"];
> payload <- b[[i]]$text;
> print(type);
> switch(type,
> scalar={print(as.numeric(payload))},
> string={print(payload)})
> }
> end foreign
> </hansl>
Cool! Here's the same sort of thing for python, though I'm sure
there's a more compact way of doing it:
<hansl>
bwrite(defbundle("x", 42, "s", "foo"), "b.xml")
foreign language=python
from lxml import etree
from collections import defaultdict
def etree_to_dict(t):
d = {t.tag: {} if t.attrib else None}
children = list(t)
if children:
dd = defaultdict(list)
for dc in map(etree_to_dict, children):
for k, v in dc.items():
dd[k].append(v)
d = {t.tag: {k: v[0] if len(v) == 1 else v
for k, v in dd.items()}}
if t.attrib:
d[t.tag].update(('@' + k, v)
for k, v in t.attrib.items())
if t.text:
text = t.text.strip()
if children or t.attrib:
if text:
d[t.tag]['#text'] = text
else:
d[t.tag] = text
return d
with open('b.xml', 'r') as f:
xml = f.read()
str = '\n'.join(xml.split('\n')[1:])
tree = etree.fromstring(str)
d = etree_to_dict(tree)
print(d)
end foreign
</hansl>
Allin
_______________________________________________
Gretl-devel mailing list -- gretl-devel@gretlml.univpm.it
To unsubscribe send an email to gretl-devel-le...@gretlml.univpm.it
Website:
https://gretlml.univpm.it/postorius/lists/gretl-devel.gretlml.univpm.it/
