Python : Creating A New Process

I am new to Python . I was supposed to create a GUI with multiple menus . On clicking a particular menu a new process should start and it should not hang the User Interface . But i

Solution 1:

import threading

classsimpleapp_tk(Tkinter.Tk):
    # .............................defOnButtonClick(self):
       thr = threading.Thread(target=self.print_deep)
       thr.start()

    defprint_deep(self):
       whileTrue:
          print'deep'

If you want to create a new process you need to create separate script that will run in separate process. I still thing that better solution will be using threads.

proc.py

whileTrue:
    print('deep')

parent_proc.py

import subprocess
import sys    

classsimpleapp_tk(Tkinter.Tk):
    # .............................defOnButtonClick(self):
        subprocess.Popen(args=['python', 'proc.py'], stdout=sys.stdout])

Solution 2:

You don't need multiple threads to start an external process. Popen() doesn't wait for the child process to end. It returns immediately. Here's a complete code example that starts/stops a tkinter progressbar on the start/end of a subprocess without using threads .

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Unrelated: to run while True: print 'deep'; time.sleep(1) without blocking the GUI (assuming print('deep') does not block for long), you could use parent.after() method:

defOnButtonClick(self):
    self._step()    

def_step(self):
    print('deep')
    self.parent.after(1000, self._step) # call _step in a second