83 lines
2.9 KiB
Python
83 lines
2.9 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
# Copyright(C) 2010 Christophe Benz
|
|
#
|
|
# This program is free software; you can redistribute it and/or modify
|
|
# it under the terms of the GNU General Public License as published by
|
|
# the Free Software Foundation, version 3 of the License.
|
|
#
|
|
# This program is distributed in the hope that it will be useful,
|
|
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
# GNU General Public License for more details.
|
|
#
|
|
# You should have received a copy of the GNU General Public License
|
|
# along with this program; if not, write to the Free Software
|
|
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
|
|
|
|
import lxml.html
|
|
|
|
from .iparser import IParser
|
|
|
|
|
|
__all__ = ['LxmlHtmlParser', 'select', 'SelectElementException']
|
|
|
|
|
|
class SelectElementException(Exception):
|
|
pass
|
|
|
|
|
|
def select(element, selector, nb=None, method='cssselect'):
|
|
"""
|
|
Select one or many elements from an element, using lxml cssselect by default.
|
|
|
|
Raises SelectElementException if not found.
|
|
|
|
@param element [obj] element on which to apply selector
|
|
@param selector [str] CSS or XPath expression
|
|
@param method [str] (cssselect|xpath)
|
|
@param nb [int] number of elements expected to be found.
|
|
Use None for undefined number, and 'many' for 1 to infinite.
|
|
@return one or many Element
|
|
"""
|
|
if method == 'cssselect':
|
|
results = element.cssselect(selector)
|
|
if nb is None:
|
|
return results
|
|
elif isinstance(nb, basestring) and nb == 'many':
|
|
if results is None or len(results) == 0:
|
|
raise SelectElementException('Element not found with selector "%s"' % selector)
|
|
elif len(results) == 1:
|
|
raise SelectElementException('Only one element found with selector "%s"' % selector)
|
|
else:
|
|
return results
|
|
elif isinstance(nb, int) and nb > 0:
|
|
if results is None:
|
|
raise SelectElementException('Element not found with selector "%s"' % selector)
|
|
elif len(results) < nb:
|
|
raise SelectElementException('Not enough elements found (%d expected) with selector "%s"' % (nb, selector))
|
|
else:
|
|
return results[0] if nb == 1 else results
|
|
else:
|
|
raise Exception('Unhandled value for kwarg "nb": %s' % nb)
|
|
else:
|
|
raise NotImplementedError('Only cssselect method is implemented for the moment')
|
|
|
|
|
|
class LxmlHtmlParser(IParser):
|
|
"""
|
|
Parser using lxml.
|
|
|
|
Note that it is not available on every systems.
|
|
"""
|
|
|
|
def parse(self, data, encoding=None):
|
|
if encoding is None:
|
|
parser = None
|
|
else:
|
|
parser = lxml.html.HTMLParser(encoding=encoding)
|
|
return lxml.html.parse(data, parser)
|
|
|
|
def tostring(self, element):
|
|
return lxml.html.tostring(element, encoding=unicode)
|