Selenium doesn't open the browser in Python - python-2.7

Question

I'm new in Python and I'm trying to use Selenium in Debian but it doesn't work, more concretely it seems to stay in a loop and nothing happens. The next script is the test that I've used:
#!/usr/bin/env python
from selenium import webdriver
browser = webdriver.Firefox()
browser.get('http://www.python.org')
When I interrupt the script the following text appears:
Traceback (most recent call last):
File "prueba_parseo.py", line 7, in browser =
webdriver.Firefox() File
"/usr/local/lib/python2.7/dist-packages/selenium/webdriver/firefox/webdriver.py",
line 154, in init
keep_alive=True)
File
"/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py",
line 140, in init
self.start_session(desired_capabilities, browser_profile)
File
"/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py",
line 229, in start_session
response = self.execute(Command.NEW_SESSION, parameters)
File
"/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py",
line 295, in execute
response = self.command_executor.execute(driver_command, params)
File
"/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/remote_connection.py",
line 464, in execute
return self._request(command_info[0], url, body=data)
File
"/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/remote_connection.py",
line 488, in _request
resp = self._conn.getresponse()
File "/usr/lib/python2.7/httplib.py", line 1111, in getresponse
response.begin()
File "/usr/lib/python2.7/httplib.py", line 444, in begin
version, status, reason = self._read_status()
File "/usr/lib/python2.7/httplib.py", line 400, in _read_status
line = self.fp.readline(_MAXLINE + 1)
File "/usr/lib/python2.7/socket.py", line 476, in readline
data = self._sock.recv(self._rbufsize)
KeyboardInterrupt
I've been searching for an answer, but nothing works. I've changed the versions of the packages, export no_proxy="localhost,127.0.0.1"
OS: Debian 5
Python: 2.7
Selenium: 3.5
Geckodriver: 0.17.0
Firefox: 52.0
I don't know what else to do or what to change.
Thank you very much!

Answer 1

My guess is that it actually all goes well and the browser is started in background. The reason why it's staying open is probably because of the default option keep_alive=True I can see in your traceback.
Try closing the browser using browser.close() or browser.quit() when you are done with the tests.
From the documentation:
Finally, the browser window is closed. You can also call quit method
instead of close. The quit will exit entire browser whereas close`
will close one tab, but if just one tab was open, by default most
browser will exit entirely.
http://selenium-python.readthedocs.io/getting-started.html#simple-usage