# Hpricot and xpath **URL:** \ **Category:** ruby-talk\ **Created:** [13 August 2008 01:45 UTC](https://rubytalk.org/t/hpricot-and-xpath/48295 "2008-08-13T01:45:06Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![Guest2](https://avatars.discourse-cdn.com/v4/letter/g/439d5e/32.png) [@Guest2](https://rubytalk.org/u/Guest2)\ **Post date:** [13 August 2008 01:45 UTC](https://rubytalk.org/t/hpricot-and-xpath/48295/1 "2008-08-13T01:45:06Z")
> tag1.rb:6: undefined method `xpath' for nil:NilClass (NoMethodError) > Do you see the nil in that line? Where is the nil coming from? Is the method > before the .xpath, on line 6, possibly returning a nil and not an Elem? > After pondering that, switch '#header' to '.header'! Hi Phlip, Thank you for your dot!!! I follow your suggestion and change to '.header' or ".header" instead of "#header" and and it works. Ruby returns the tag's path like this: /tag1/tag2/div. But I see nowhere in the document about using "." and "#" in xpath() or css\_path(). Do I miss something in the docucment? Li > **···** > > Subject: Re: Hpricot and xpath ---
**Author:** ![Phlip1](https://avatars.discourse-cdn.com/v4/letter/p/df788c/32.png) [@Phlip1](https://rubytalk.org/u/Phlip1)\ **Post date:** [13 August 2008 03:42 UTC](https://rubytalk.org/t/hpricot-and-xpath/48295/2 "2008-08-13T03:42:26Z")
chen li wrote: > I follow your suggestion and change to '.header' or ".header" instead of "#header" and and it works. Ruby returns the tag's path like this: /tag1/tag2/div. But I see nowhere in the document about using "." and "#" in xpath() or css\_path(). Do I miss something in the docucment? That's just the thing. I studied the crap out of HTML, XHTML, and light CSS, and never learned until encountering assert\_select that CSS has its own query notation. Others with different career paths have learned nothing but - and they all assume you know the same things. Hpricot can handle \_light\_ XPath, and can handle various CSS Selector notations. The documenters have all assumed that someone else taught you how they work. So google for "CSS Selector", without x-ref'ing Hpricot! > **···** > > -- >    Phlip