.. _grab_response_search:

Searching the response body
===========================

String search
-------------

With the `doc.text_search` method, you can find out if the response body contains a certain string or not::

    >>> g = Grab('<h1>test</h1>')
    >>> g.doc.text_search(u'tes')
    True

If you prefer to raise an exception if string was not found, then use the `doc.text_assert` method::

    >>> g = Grab('<h1>test</h1>')
    >>> g.doc.text_assert(u'tez')
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
      File "/home/lorien/web/grab/grab/document.py", line 109, in text_assert
        raise DataNotFound(u'Substring not found: %s' % anchor)
    grab.error.DataNotFound: Substring not found: tez

By default, all text search methods operate with unicode; i.e., you should pass
unicode arguments to these methods and these methods will search inside document's
body converted to unicode. There is an option to work with raw bytes, just pass
`byte=True` to any method::

    >>> g = Grab('<h1>test</h1>')
    >>> g.doc.text_search(b'tez', byte=True)


Regexp Search
-------------

You can search for a regular expression with `doc.rex_search` method that accepts compiled regexp object or just a text of regular expression::

    >>> g = Grab('<h1>test</h1>')
    >>> g.doc.rex_search('<.+?>').group(0)
    u'<h1>'

Method `doc.rex_text` returns you text contents of `.group(1)` of the found match object::

    >>> g = Grab('<h1>test</h1>')
    >>> g.doc.rex_text('<.+?>(.+)<')
    u'test'
    

Method `doc.rex_assert` raises `DataNotFound` exception if no match is found::

    >>> g = Grab('<h1>test</h1>')
    >>> g.doc.rex_assert('\w{10}')
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
      File "/home/lorien/web/grab/grab/document.py", line 189, in rex_assert
        self.rex_search(rex, byte=byte)
      File "/home/lorien/web/grab/grab/document.py", line 180, in rex_search
        raise DataNotFound('Could not find regexp: %s' % regexp)
    grab.error.DataNotFound: Could not find regexp: <_sre.SRE_Pattern object at 0x7fa40e97d1f8>