= Using XPath in Markup =

Markup provides basic [http://www.w3.org/TR/xpath XPath] support for matching and querying event streams.

== Limitations ==

Due to the streaming nature of the processing model, Markup uses only a subset of the [http://www.w3.org/TR/xpath XPath 1.0] language.

In particular, only the following axes are supported:
 * `attribute`
 * `child`
 * `descendant`
 * `descendant-or-self`
 * `namespace` (not completed yet)
 * `self`

In addition, Markup does not (yet) support numeric types in XPath: everything is treated as text or booleans. For that reason, [http://www.w3.org/TR/xpath#NT-RelationalExpr relational] or [http://www.w3.org/TR/xpath#NT-AdditiveExpr additive] operators such as `>`, `<`, or `<=`.

== Querying Streams ==

{{{
#!python
from markup.input import XML

doc = XML('''<doc>
 <items count="2">
      <item status="new">
        <summary>Foo</summary>
      </item>
      <item status="closed">
        <summary>Bar</summary>
      </item>
  </items>
</doc>''')
print doc.select('items/item[@status="closed"]/summary/text()')
}}}

This would result in the following output:

{{{
#!xml
Bar
}}}

== Matching in Templates ==

See MarkupTemplates#py:match

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See also: MarkupGuide, MarkupStream