python 如何while循环while true，一起运行多个函数

Question

def function():
    while True:  
        ...omission...(this function is repeated permanently)
i =0
while i < 4:
    driver.execute_script("""window.open("URL")""")
    driver.switch_to.window(driver.window_handles[-1])
    time.sleep(1)
    function()
    time.sleep(1)
    i += 1  #open new tab and run function.

it doesn't work because while true loop is repeated permanently. Is there any ways to run multiple functions together? https://imgur.com/a/4SIVekS This picture shows what I want

Answer 1

I don't understand your question because I don't understand what your function is supposed to do.

while True:

will always create an infinite loop. "while" is a command that tells python to loop through the following block so long as the expression following it evaluates to True. True always evaluates to True.

It seems like you want to use a conditional, like you do in "while x < 4".

x < 4

...is an expression that evaluates to true when x is less than 4, and false if x is not less than 4. Everything below the line:

while x < 4:

will then run if x is less than 4, and when it's done running that code, it will go back and evaluate if x is less than 4 again, and if it is, run the code again. To include another while loop inside of that loop, that new loop also needs an expression to evaluate. If you want to evaluate the same expression, write it out:

while x < 4:
    # do something
    while x < 4:
        #do more things
    # do even more things
    # change x at some point, or else you're in an infinite loop.

However, there's no reason to do that specifically, because you're already doing it. All of the code is only running when x < 4, so checking that condition again right there is redundant, and doing it in another loop doesn't make sense. If the inside loop is also incrementing x, then the outside loop won't loop and doesn't need to increment x.

Also, if you want a function to check a condition based on a variable outside the function, you'll want to pass things to that function.

Answer 2

According to your picture, what you want is to launch the function a set number of times (4?), and run those in parrallel. On a single core, as is the normal behavior, straight up parallel processing is impossible. You need to access other cores and manage a decentralized processing. while is useless there. I'm worried the level of difficulty is over your current skills, but here we go.

The overall flow that you (probably, depends on the actual memory safety of your functions) need is:
- to create a thread pool with the set number of threads for the number of runs you want.
- indicate the function you need to run
- start them, making sure the start itself is non-blocking.
- ensure one functions's processing doesn't impact another's results. race conditions are a common problem.
- gather results, again, in a non-blocking way.

You can use several methods. I highly recommend you read up a lot on the following documentations.

Threading:
https://docs.python.org/3/library/threading.html

Multiprocessing:
https://docs.python.org/3/library/multiprocessing.html