Multi tool use

XPATH syntax validator in Python

I develop a crawler with many actions. Many xpaths are involving and for this reason I use a json file for storing. Then crawler start running I would like to make a basic syntax check (before xpath usage) on xpaths and raise error for invalid xpaths.

for example:

xpath1 = '//*[@id="react-root"]/section'
xpath2 = '//*[[@id="react-root"]/section'
xpath3 = '//*[@id="react-root"]section'


from these xpaths only xpath1 is valid

is there any module or regex which does this kind of validation?

1 Answer
1

You can compile the xpath strings with lxml.etree.XPath which will raise an exception if the syntax is incorrect:

lxml.etree.XPath

>>> import lxml.etree
>>> lxml.etree.XPath('//*[@id="react-root"]/section')
//*[@id="react-root"]/section
>>> lxml.etree.XPath('//*[[@id="react-root"]/section')
Traceback (most recent call last):
...
lxml.etree.XPathSyntaxError: Invalid expression
>>> lxml.etree.XPath(r'//*[@id="react-root"]section')
Traceback (most recent call last):
...
lxml.etree.XPathSyntaxError: Invalid expression


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