Running a process in pythonw with Popen without a console

According to Python 2.7 documentation and Python 3.7 documentation, you can influence how Popen creates the process by setting creationflags. In particular, the CREATE_NO_WINDOW flag would be useful to you.

variable = subprocess.Popen(
   "CMD COMMAND", 
   stdout = subprocess.PIPE, creationflags = subprocess.CREATE_NO_WINDOW
)

From here:

import subprocess

def launchWithoutConsole(command, args):
    """Launches 'command' windowless and waits until finished"""
    startupinfo = subprocess.STARTUPINFO()
    startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
    return subprocess.Popen([command] + args, startupinfo=startupinfo).wait()

if __name__ == "__main__":
    # test with "pythonw.exe"
    launchWithoutConsole("d:\\bin\\gzip.exe", ["-d", "myfile.gz"])

Note that sometimes suppressing the console makes subprocess calls fail with "Error 6: invalid handle". A quick fix is to redirect stdin, as explained here: Python running as Windows Service: OSError: [WinError 6] The handle is invalid

just do subprocess.Popen([command], shell=True)