[selenium-users] Selenium now failing on Python

[m***@baskerville.org]

I have been using Selenium occasionally from Python 3.7 using PyCharm under
Windows 10 for about a year and until the last week it worked without
issues.. I recently upgraded to PyCharm 2018.3 and Python 3.7 and also
updated Selenium and it now fails. (I don't remember if I tried running it
between any of those three upgrade.) I will note that I also have the
Python 3.5 interpreter installed.


When I execute the line:

browser=webdriver.Firefox()

I get one of two messages:

From a new program written since the upgrade:

"selenium.common.exceptions.WebDriverException: Message:
'geckodriver.exe' executable needs to be in PATH."
From an older program that *did* work a week ago, I get the message:

"selenium.common.exceptions.SessionNotCreatedException: Message:
Unable to find a matching set of capabilities"

This latter program is still using the 3.5 interpreter.


I have tried this from the Python prompt and get basically the same
messages.


I have tried several supposed fixes I found on the Internet:
* I confirmed that Selenium is the latest version
* I downloaded and installed the latest geckodriver.exe
* I rebooted
* I confirmed that the geckdriver.exe's directory was on the system path.
(It's in c:/windows/system32. I can type "geckodriver" at a command prompt
and it finds an executable. I don't see duplicate executables on my system.)

* I changed the call to
browser=webdriver.Firefox(executable_path=r'C:\Windows\system32\geckodriver.exe')

None helped.


Can anyone suggest something?

[m***@baskerville.org]

I'm not very sure what's going on here, but after a lot of fiddling, I
discovered that backs down to Python 3.5 solved the problem. The code runs
with 3.5, fails when I switch to 3.7, and works again when I go back to 3.5.