> because a set avoids duplicates. If you say "I want to document my
> achievements for posterity" I would recommend that you print to a file
> rather than append to a list and the original code could be changed to
>
> with open("somefile") as f:
> for achievement in my_achievements:
> print(achievement.description, file=f)
>
>
> Back to my coding hint: Don't repeat yourself. If you move the pieces
>
> >> > meetattrs = ('id', 'venue', 'date', 'rail', 'weather',
> >> > 'trackcondition')
> >>
> >> > meet = d('meeting')
> >>
> >> > meetdata = [[meet.eq(i).attr(x)
> >> > for x in meetattrs] for i in range(len(meet))]
>
> into a function
>
> def extract_attrs(nodes, attrs):
> return [[nodes.eq(i).attr(name) for name in attrs]
> for i in range(len(nodes))]
>
> You can reuse it for clubs, races, etc.:
>
> meetdata = extract_attrs(d("meeting"), meetattrs)
> racedata = extract_attrs(d("race"), raceattrs)
>
> If you put the parts into a dict you can generalize even further:
>
> tables = {
> "meeting": ([], meetattrs),
> "race": ([], raceattrs),
> }
> for name, (data, attrs) in tables.items():
> data.extend(extract_attrs(d(name), attrs))
>
I find that really cool. Reads well to, hadn't considered approaching it that
way at all.
> So you want to go from a tree structure to a set of tables that preserves
> the structure by adding foreign keys. You could try a slightly different
> approach, something like
>
> for meeting in meetings:
> meeting_table.append(...meeting attrs...)
> meeting_id = ...
> for race in meeting:
> race_table.append(meeting_id, ...meeting attrs...)
> race_id = ...
> for nomination in race:
> nomination_table.append(race_id, ...nomination attrs...)
>
> I don't know how to spell this in PyQuery -- with lxml you could do
> something like
>
> meeting_table = []
> race_table = []
> nomination_table = []
> tree = lxml.etree.parse(filename)
> for meeting in tree.xpath("/meeting"):
> meeting_table.append([meeting.attrib[name] for name in meetattrs])
> meeting_id = meeting.attrib["id"]
> for race in meeting.xpath("./race"):
> race_table.append(
> [meeting_id] + [race.attrib[name] for name in raceattrs])
> race_id = race.attrib["id"]
> for nomination in race.xpath("./nomination"):
> nomination_table.append(
> [race_id]
> + [nomination.attrib[name] for name in horseattrs])
>
> Not as clean and not as general as I would hope -- basically I'm neglecting
> my recommendation from above -- but if it works for you I might take a
> second look later.
I need to play around with this just to understand it more, really like it.
Might try and implement your advice from before and put it in a function.
Sayth
--
https://mail.python.org/mailman/listinfo/python-list
