Change user agent with selenium webdriver and python - python-2.7

Question

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import Select
import os
xpaths = { 'video' : "//video[#id='video']",
}
from selenium import webdriver
profile = webdriver.FirefoxProfile()
profile.set_preference("general.useragent.override", "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2227.0 Safari/537.36")
driver = webdriver.Firefox(profile)
mydriver = webdriver.Firefox()
baseurl = "XXXX"
mydriver.get(baseurl)
It's not changing the user agent. I want the user agent to be chrome. I don't know what's wrong...
And also, here's what i'd like it to do: Go to the website, if it redirects to another url > Goes back to main page and keeps doing that until it finds (id:video)
I have not implemented this yet because i have no idea how to...
The website i'm trying to automate got a vid and it appears sometimes. What i'd like this to do is keep visiting the website until it finds the id:video clicks it and waits.
Help is appreciated :)

Answer 1

You are navigating to your application URL using the wrong firefox instance - mydriver. Using the correct firefox instance (with required profile setting) should do the work (which is driver in your case).
Below is the correct code:
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import Select
import os
xpaths = { 'video' : "//video[#id='video']",
}
profile = webdriver.FirefoxProfile()
profile.set_preference("general.useragent.override", "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2227.0 Safari/537.36")
driver = webdriver.Firefox(profile)
# the below line is not required
#mydriver = webdriver.Firefox()
baseurl = "XXXX"
# navigate to url with 'driver' instead of 'mydriver'
driver.get(baseurl)
If you change your baseurl to "http://whatsmyuseragent.com/", you will be able to right away see if the user agent change is reflected correctly.
Hope this helps!