title: Why can't I find an input element with a placeholder in selenium?
body: <p>In a webpage I have the following element:</p>
  
  <pre><code>&lt;input placeholder="Search in your collabs" class="md-input" type="text"&gt;
  </code></pre>
  
  <p>which I try to select by the following piece of code (in <code>python</code>):</p>
  
  <pre><code>elem = browser.find_element_by_xpath("//input[@placeholder='Search in your collabs']")
  </code></pre>
  
  <p>but when running the code I get the following error:</p>
  
  <pre><code>NoSuchElementException: Message: Unable to locate element: //input[@placeholder='Search in your collabs']
  </code></pre>
  
  <p>The element I am looking for is inside an iframe which I selected before correctly (I did another <code>find_element_by_xpath</code> before that with some other attributes). In detail, what I did before was:</p>
  
  <pre><code>browser.switch_to_frame(browser.find_element_by_id("clb-iframe-workspace"));
  </code></pre>
  
  <p>So but why is this not working now?</p>