title: Selenium python find_element_by_class_name() stopped working from v 2.2 to 2.21 -- cannot use 'Compound Class Name'
body: <p>I am using Selenium's python library to scrape data from a html page in Firefox.</p>
  <p>I have had to update from Selenium 2.0 to 2.21 because the server has updated Firefox.</p>
  <p>In v 2.21 calls to <code>find_element_by_class_name(&quot;grid-cell-inner grid-col-name&quot;)</code> fails with:</p>
  <pre><code>selenium.common.exceptions.WebDriverException: Message: u'Compound class names not permitted'
  </code></pre>
  <p>The class name of the element I am trying to access is <code>grid-cell-inner grid-col-name</code></p>
  <p>The call to <code>find_element_by_class_name()</code> worked in v 2.2, so the logic is correct, and the data used to be found OK.  Something changed in v 2.21.</p>
  <p>All the Selenium examples give simple examples with class name <code>foo</code> etc, and none with the type of name I need to access.</p>
  <p>Why did Selenium stop supporting finding classes with names like <code>grid-cell inner grid-col-name</code>, and what it their solution?</p>
  <p>Can someone please help me to find elements with &quot;compound&quot; class names?</p>