How to solve the Python Selenium error which
<p>I am trying to use the selenium to deal with some website using JavaScript codes. To begin with,I use simple example as below</p>

<pre><code>from selenium import webdriver

browser = webdriver.Firefox()

browser.get('http://www.yahoo.com')

browser.quit()
</code></pre>

<p>While this even does not work. The error msg is shown as below. I think I may missed something in selenium or something else. Could you bring me some light on this?</p>

<pre><code>Traceback (most recent call last):
  File "/home/rnie/webdriver-tutorial-1x.py", line 3, in &lt;module&gt;
    browser = webdriver.Firefox()
  File "/usr/lib/python3.5/site-packages/selenium/webdriver/firefox/webdriver.py", line 145, in __init__
    keep_alive=True)
  File "/usr/lib/python3.5/site-packages/selenium/webdriver/remote/webdriver.py", line 92, in __init__
    self.start_session(desired_capabilities, browser_profile)
  File "/usr/lib/python3.5/site-packages/selenium/webdriver/remote/webdriver.py", line 179, in start_session
    response = self.execute(Command.NEW_SESSION, capabilities)
  File "/usr/lib/python3.5/site-packages/selenium/webdriver/remote/webdriver.py", line 236, in execute
    self.error_handler.check_response(response)
  File "/usr/lib/python3.5/site-packages/selenium/webdriver/remote/errorhandler.py", line 192, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: connection refused
</code></pre>

<p>I checked the <code>"geckodriver.log"</code>, and it shows following error messages:</p>

<pre><code>1479623778556   geckodriver INFO    Listening on 127.0.0.1:49723
1479623778625   mozprofile::profile INFO    Using profile path /tmp/rust_mozprofile.WMDGNONHQTud
1479623778628   geckodriver::marionette INFO    Starting browser /usr/bin/firefox
1479623778641   geckodriver::marionette INFO    Connecting to Marionette on localhost:35691
No protocol specified
Unable to init server: Could not connect: Connection refused
Error: cannot open display: :0
</code></pre>