Freezing a dual-mode (GUI and console) application using cx_Freeze

Question

Hi,

I've developed a Python application that runs both in the GUI mode and the console mode. If any arguments are specified, it runs in a console mode else it runs in the GUI mode.

I've managed to freeze this using cx_Freeze. I had some problems hiding the black console window that would pop up with wxPython and so I modified my setup.py script like this:

import sys

from cx_Freeze import setup, Executable

base = None
if sys.platform == "win32":
    base = "Win32GUI"

setup(
        name = "simple_PyQt4",
        version = "0.1",
        description = "Sample cx_Freeze PyQt4 script",
        executables = [Executable("PyQt4app.py", base = base)])

This works fine but now when I try to open up my console and run the executable from there, it doesn't output anything. I don't get any errors or messages so it seems that cx_Feeze is redirecting the stdout somewhere else.

Is is possible to get it to work with both mode? Nothing similar to this seems to be documented anywhere. :(

Thanks in advance.

Mridang

Answer 1

Raymond Chen has written about this: http://blogs.msdn.com/b/oldnewthing/archive/2009/01/01/9259142.aspx. In short, it's not possible directly under Windows but there are some workarounds.

I'd suggest shipping two executables - cli and gui one.

Answer 2

I found this bit on this page:

Tip for the console-less version: If you try to print anything, you will get a nasty error window, because stdout and stderr do not exist (and the cx_freeze Win32gui.exe stub will display an error Window). This is a pain when you want your program to be able to run in GUI mode and command-line mode. To safely disable console output, do as follows at the beginning of your program:

try:
    sys.stdout.write("\n")
    sys.stdout.flush()
except IOError:
    class dummyStream:
        ''' dummyStream behaves like a stream but does nothing. '''
        def __init__(self): pass
        def write(self,data): pass
        def read(self,data): pass
        def flush(self): pass
        def close(self): pass
    # and now redirect all default streams to this dummyStream:
    sys.stdout = dummyStream()
    sys.stderr = dummyStream()
    sys.stdin = dummyStream()
    sys.__stdout__ = dummyStream()
    sys.__stderr__ = dummyStream()
    sys.__stdin__ = dummyStream()

This way, if the program starts in console-less mode, it will work even if the code contains print statements. And if run in command-line mode, it will print out as usual. (This is basically what I did in webGobbler, too.)