Le 10/05/2012 11:59, Simon Sapin a écrit :
Hi,
When using a custom XPath function (as lxml.cssselect does for lower-case) I get a strange XPathFunctionError error when using a compiled XPath object more than once.
Here is a minimal test case:
from lxml import etree, html
def _make_lower_case(context, s): return s.lower()
ns = etree.FunctionNamespace('http://codespeak.net/lxml/css/') ns.prefix = 'css' ns['lower-case'] = _make_lower_case
#doc = html.parse('/home/simon/css3-backgrounds.html') doc = html.parse('http://www.w3.org/TR/css3-background/')
expr = etree.XPath('//*[css:lower-case(name(.)) = "li"]') print('first call') expr(doc) print('second call') expr(doc) print('third call') expr(doc)
And the output I get with lxml 2.3.4:
first call second call Traceback (most recent call last): File "xpath_lower.py", line 20, in<module> expr(doc) File "xpath.pxi", line 466, in lxml.etree.XPath.__call__ (src/lxml/lxml.etree.c:119238) File "xpath.pxi", line 235, in lxml.etree._XPathEvaluatorBase._handle_result (src/lxml/lxml.etree.c:117011) File "lxml.etree.pyx", line 280, in lxml.etree._ExceptionContext._raise_if_stored (src/lxml/lxml.etree.c:7454) lxml.etree.XPathFunctionError: XPath function '{b'\xd0\x85?\x01'}b'lower-case'' not found
Note that the '\xd0\x85?\x01' string looks random and changes every time I run the script.
Is something wrong in my code?
In case it helps, here are the version numbers: Python : sys.version_info(major=3, minor=2, micro=3, releaselevel='final', serial=0) lxml.etree : (2, 3, 4, 0) libxml used : (2, 7, 8) libxml compiled : (2, 7, 8) libxslt used : (1, 1, 26) libxslt compiled : (1, 1, 26) This is on Linux x64 and the random string is always 4 bytes long. I’ve seen similar issues that were caused by a 32bit vs. 64bit bug where sizeof(int) (8 in 64bit) in was used instead of sizeof(int32) or similar. -- Simon Sapin