title: Upload file with Selenium Webdriver Python
body: <p>I have tried the method from this page:
  <a href="https://stackoverflow.com/questions/8428102/upload-file-with-selenium-in-python">Upload file with Selenium in Python</a></p>
  
  <p>Code:</p>
  
  <pre><code>file_button = browser.find_element_by_id('fileUploadProxy')
  file_button.send_keys('/Users/home/Downloads/1-Students-and-Parent-Email.csv')
  </code></pre>
  
  <p>But I get the following error:</p>
  
  <pre><code>Traceback (most recent call last):
    File "test.py", line 110, in &lt;module&gt;
      upload_students_results('Surname, Name')
    File "test.py", line 91, in upload_students_results
      file_button.send_keys('/Users/home/Downloads/1-Students-and-Parent-Email.csv')
    File "/Library/Python/2.7/site-packages/selenium/webdriver/remote/webelement.py", line 349, in send_keys
  'value': keys_to_typing(value)})
    File "/Library/Python/2.7/site-packages/selenium/webdriver/remote/webelement.py", line 493, in _execute
  return self._parent.execute(command, params)
    File "/Library/Python/2.7/site-packages/selenium/webdriver/remote/webdriver.py", line 249, in execute
  self.error_handler.check_response(response)
    File "/Library/Python/2.7/site-packages/selenium/webdriver/remote/errorhandler.py", line 193, in check_response
  raise exception_class(message, screen, stacktrace)
  selenium.common.exceptions.WebDriverException: Message: unknown error: cannot focus element
    (Session info: chrome=58.0.3029.96)
    (Driver info: chromedriver=2.29.461585 (0be2cd95f834e9ee7c46bcc7cf405b483f5ae83b),platform=Mac OS X 10.12.4 x86_64)
  </code></pre>