可以为子进程 (Windows) 抑制 Python 版本消息吗？

Question

I am using multiprocessing to calculate a large mass of data; ie I periodically spawn a process so that the total number of processes is equal to the number of CPU's on my machine. I periodically print out the progress of the entire calculation... but this is inconveniently interspersed with Python's welcome messages from each child! To be clear, this is a Windows specific problem due to how multiprocessing is handled.

Eg

> python -q my_script.py

Python Version: 3.7.7 on Windows

Then many subsequent duplicates of the same version message print; one for each child process. How can I suppress these?

I understand that if you run Python on the command line with a -q flag, it suppresses the welcome message; though I don't know how to translate that into my script.

EDIT:

I tried to include the interpreter flag -q like so:

multiprocessing.set_executable(sys.executable + ' -q')

Yet to no avail. I receive a FileNotFoundError which tells me I cannot pass options this way due to how they check arguments.

Anyways, here is the relevant section of code (It's an entire function):

def _parallelize(self, buffer, func, cpus):
    ## Number of Parallel Processes ##
    cpus_max = mp.cpu_count()
    cpus = min(cpus_max, cpus) if cpus else int(0.75*cpus_max)

    ## Total Processes to-do ##
    N = ceil(self.SampleLength / DATA_MAX)  # Number of Child Processes
    print("N: ", N)
    q = mp.Queue()  # Child Process results Queue

    ## Initialize each CPU w/ a Process ##
    for p in range(min(cpus, N)):
        mp.Process(target=func, args=(p, q)).start()

    ## Collect Validation & Start Remaining Processes ##
    for p in tqdm(range(N)):
        n, data = q.get()  # Collects a Result

        i = n * DATA_MAX  # Shifts to Proper Interval

        buffer[i:i + len(data)] = data  # Writes to open HDF5 file

        if p < N - cpus:  # Starts a new Process
            mp.Process(target=func, args=(p + cpus, q)).start()

SECOND EDIT:

I should probably mention that I'm doing everything within an anaconda environment.

Answer 1

The message is printed on interactive startup.

A spawned process does inherit some flags from the child process. But looking at the code in multiprocessing it does not seem possible to change these parameters from within the program.

So the easiest way to get rid of the messages should be to add the -q option to the original python invocation that starts your program. I have confirmed that the -q flag is inherited.

So that should suppress the message for the original process and the children that it spawns.

Edit: If you look at the implementation of set_executable , you will see that you cannot add or change arguments that way. :-(

Edit2: You wrote:

I'm doing everything within an anaconda environment.

You you mean a virtual environment, or some kind of fancy IDE like spyder?

If you ever have a Python problem, first try reproducing it in plain CPython , running from the command line. IDE's and fancy environments like anaconda sometimes do weird things when running Python.