How do I programmatically check for open browser instances on a Windows machine?

问题

I wrote a GUI automation script in python that opens a web browser, does some tests in the browser and then closes the browser. It does so in a loop going up through hundreds of thousands of iterations.

I've run into problems where the program would hang and I would get no browser instances open or sometimes up to 20 instances open. I would like to create an error check to make sure there is only one browser instance open at a time (kill the browser completely and restart the iteration if there are many instances open and/or make sure a browser instance is open before going through an iteration of the loop).

The PID for the browser obviously changes through every iteration of the loop and as far as I know, there is no way to assign PIDs. Another solution I thought of is making a system call to the terminal and somehow utilizing the tasklist and taskkill commands but have still not figured out a way to do what I want.

Any suggestions would be greatly appreciated!

Update:

I understand I can search windows processes by name but how would I put that into a boolean expression like

if tasklist contains firefox.exe
    taskkill firefox.exe
else
    open firefox

Second Update:

I have the following that I was able to code in Ruby which works:

    if system('tasklist | find "firefox.exe"') == true
        a = 1
    elsif system('tasklist | find "firefox.exe"') == false
        a = 0
    end

How would I accomplish this in Python?

Answer I was looking for:

b = (str(os.system('tasklist | find "firefox.exe"')))
if b == '1':
    b = 'false'
elif b == '0':
    b = 'true'
print b

回答1:

Ive been doing similar things

i think you may want pywinauto

from pywinauto.findwindows import find_windows

find_windows(best_match='YOURWINDOWNAMEHERE')

this will raise an exception if YOURWINDOWNAMEHERE is not open

edit: actually for firefox or chrome, it only works if "YOURWINDOWNAMEHERE" is whatever the page you are on is for example this page is "python - How do i programmatically ..."

if it finds it, it will return an int, as far as i know this int is supposed to be able to reference to the window.

example:.

>>>find_windows(best_match="calculator")    #this gets an exception

# ::I manually open Calculator now ::

>>>find_windows(best_match="calculator")

[12345] #orwhatever process number it gets