Question

Two files. Each runs new window and works by itself. I need to run them both.
When I run first.pyw, only one (second) window is shown.

Is it possible two run them both?

first.pyw:

import sys
from PyQt4.QtGui import *
import second

class first(QWidget):
    def __init__(self, parent=None):
        QWidget.__init__(self, parent)
        self.setWindowTitle('first')

app = QApplication(sys.argv)
firstApp = first()
firstApp.show()
sys.exit(app.exec_())

second.pyw:

import sys
from PyQt4.QtGui import *

class second(QWidget):
    def __init__(self, parent=None):
        QWidget.__init__(self, parent)
        self.setWindowTitle('second')

app2 = QApplication(sys.argv)
secondApp = second()
secondApp.show()
sys.exit(app2.exec_())

How can I run two applications that are in different modules?

Answer 1

You can only run a single application at a time, although your application can have multiple top-level windows. The QCoreApplication docs say that:

…there should be exactly one QCoreApplication object.

This also holds true for QApplication as it derives from QCoreApplication. You can get access to that application through the QCoreApplication.instance() method or the qApp macro in C++.

What do you expect to get out of having two different applications running? Instead, you could have each module provide a top-level window that then gets displayed by the application launcher.