Class JQueryTranslator

pyquery/cssselectpatch.py:44–469

This class is used to implement the css pseudo classes (:first, :last, ...) that are not defined in the css standard, but are defined in the jquery API.

class JQueryTranslator(cssselect_xpath.HTMLTranslator):
    """This class is used to implement the css pseudo classes
    (:first, :last, ...) that are not defined in the css standard,
    but are defined in the jquery API.
    """

    xpathexpr_cls = XPathExpr

    def xpath_first_pseudo(self, xpath):
        """Matches the first selected element::

            >>> from pyquery import PyQuery
            >>> d = PyQuery('<div><p class="first"></p><p></p></div>')
            >>> d('p:first')
            [<p.first>]

        ..
        """
        xpath.add_post_condition('position() = 1')
        return xpath

    def xpath_last_pseudo(self, xpath):
        """Matches the last selected element::

            >>> from pyquery import PyQuery
            >>> d = PyQuery('<div><p></p><p class="last"></p></div>')
            >>> d('p:last')
            [<p.last>]

        ..
        """
        xpath.add_post_condition('position() = last()')
        return xpath

    def xpath_even_pseudo(self, xpath):
        """Matches even elements, zero-indexed::

            >>> from pyquery import PyQuery
            >>> d = PyQuery('<div><p></p><p class="last"></p></div>')
            >>> d('p:even')
            [<p>]

        ..
        """
        # the first element is 1 in xpath and 0 in python and js
        xpath.add_post_condition('position() mod 2 = 1')
        return xpath

    def xpath_odd_pseudo(self, xpath):
        """Matches odd elements, zero-indexed::

            >>> from pyquery import PyQuery
            >>> d = PyQuery('<div><p></p><p class="last"></p></div>')
            >>> d('p:odd')
            [<p.last>]

        ..
        """