libearth parser refactoring idea

gistfile1.py

import emails.utils

from ..compat import string_type
from ..feed import Entry, Feed, Person, Text
from .base import parser


parse_rss = parser()


@parse_rss.path('channel')
def parse_channel(element, parent):
    assert isinstance(parent, string_type), 'parent must be feed_url'
    return Feed(id=parent)


@parse_channel.path('item')
def parse_item(element, parent):
    assert isinstance(parent, Feed), 'parent must be Feed'
    entry = Entry()
    parent.entries.append(entry)
    return entry


@parse_channel.path('title')
@parse_item.path('title')
def parse_title(element, parent):
    assert isinstance(parent, (Feed, Entry)), 'parent must be Feed or Entry'
    parent.title = Text(value=element.text)


@parse_channel.path('managingEditor', attr='contributors')
@parse_channel.path('webMaster', attr='contributors')
@parse_item.path('author', attr='authors')
def parse_person(element, parent, attr):
    assert isinstance(parent, (Feed, Entry)), 'parent must be Feed or Entry'
    name, email_addr = email.utils.parseaddr(element.text)
    if '@' not in email_addr:
        if not name:
            name = email_addr
        email_addr = None
    if not name:
        name = email_addr
    if name:
        person = Person(name=name, email=email_addr or None)
        getattr(parent, attr).append(person)


@parse_channel.path('category')
@parse_item.path('category')
def parse_category(element, parent):
    category = Category(
        term=element.text,
        scheme_uri=element.attrib.get('domain')
    )
    parent.categories.append(category)