检查特定的 Python 脚本是否已经在运行

Question

How can I check, from a Python script, if another specific Python script is running?

def running():
    for q in psutil.process_iter():
        print q
        if q.name() == 'server_class.py':
            return True
    return False

I have tried that but the program is called "python" and not the name of the script.

Answer 1

The python script file will be part of the command line. You can try something along these lines:

def running():

    for q in psutil.process_iter():
        if q.name() == 'python':
            print q.cmdline()
            if len(q.cmdline())>1 and 'server_class.py' in q.cmdline()[1]:
                return True

    return False

I am using in just for the example. You might want to match the full path.

Answer 2

Case: When you want to exit the script, if a previous instance is already running:

def already_running(script_name):
num_instance = 0
for q in psutil.process_iter():
    if 'python' in q.name():
        if len(q.cmdline()) > 1 and script_name in q.cmdline()[1]:
            num_instance += 1
return num_instance > 1

What it does:

1. It checks for the number of instances of the script_name currently running. If you are calling this from file xyz.py and sending xyz.py as argument, remember the current instance will also be counted

2. If num_instance > 1, you have a previous instance running.

Hope this is useful.