[Tutor] how to move an executable into path

[Benjamin Fishbein]

Everything was going fine with my selenium webdriver programs, but then today I updated to Firefox 50. Everything stopped working. So I updated to selenium 3, hoping this would work. But apparently I need something called geckodriver.
I managed to download this, but it’s in the wrong place: in my downloads folder.
So here’s what happens when I try to do anything with selenium:
>>> from selenium import webdriver
>>> driver=webdriver.Firefox()

Traceback (most recent call last):
  File "<pyshell#342>", line 1, in <module>
    driver=webdriver.Firefox()
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/selenium/webdriver/firefox/webdriver.py", line 135, in __init__
    self.service.start()
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/selenium/webdriver/common/service.py", line 71, in start
    os.path.basename(self.path), self.start_error_message)
WebDriverException: Message: 'geckodriver' executable needs to be in PATH.

So I’m not sure where the geckodriver file needs to go. Can it be anywhere on the path? could I just put it in the site-packages folder for example?
And here’s the big problem: all of these folders are hidden, and I have no idea how to get into them.

I’m on a mac and using python2.7.

I should probably learn how to handle paths and file systems, etc., but right now I just want to get my programs running again.
Any help is greatly appreciated.

-Ben