An url is launched correctly through selenium IDE , but not through script

The type of error you are observing seems to me arising from the mismatch between Selenium, geckodriver and Firefox versions.

As per the Release Notes Selenium v3.6.0 should go well with geckodriver v.0.18.0 (where as geckodriver v.0.19.0 is recommended).

But geckodriver v.0.18.0 Release Notes clearly mentions the following:

geckodriver now recommends Firefox 53 and greater geckodriver compatible with Firefox 56 and greater

So upgrading your Firefox to v53+ level will definitely solve your issue.

Update:

Based on your comment you can change the locator for username field to either of the following:

1. css_selector

   driver.find_element_by_css_selector("input[name=username]")

2. xpath

   driver.find_element_by_xpath("//input[@name='username']")

Chances are your driver is trying to grab the username field after the first load, fails with an exception and shuts it down before the redirect. It needs to wait. You could try:

from selenium.webdriver.support import expected_conditions as ECfrom selenium.webdriver.support.ui import WebDriverWait...def test_worked2(self):    driver = self.driver    driver.get(base_url)    WebDriverWait(self.driver, 10).until(EC.presence_of_element_located((By.NAME, 'username'))).send_keys("xxx")

i was able to resolve this issue by using Firefox profile, i don't know what difference it made, but it actually worked.

Link to create Firefox profile

http://kb.mozillazine.org/Creating_a_new_Firefox_profile_on_Windows

Below is the code

from selenium import webdriverfp = webdriver.FirefoxProfile('C:/Users/<user name>/AppData/Roaming/Mozilla/Firefox/Profiles/abc3defghij2.ProfileName')driver = webdriver.Firefox(fp)driver.get("https://www.example.com/membersarea")