Make qwidget in new window in PyQt4

Question

I'm trying to make a class that extends qwidget, that pops up a new window, I must be missing something fundamental,

class NewQuery(QtGui.QWidget):
 def __init__(self, parent):
  QtGui.QMainWindow.__init__(self,parent)
  self.setWindowTitle('Add New Query')
  grid = QtGui.QGridLayout()
  label = QtGui.QLabel('blah')
  grid.addWidget(label,0,0)
  self.setLayout(grid)
  self.resize(300,200)

when a new instance of this is made in main window's class, and show() called, the content is overlaid on the main window, how can I make it display in a new window?

Answer 1

Your superclass initialiser is wrong, you probably meant:

class NewQuery(QtGui.QWidget):
    def __init__(self, parent):
        QtGui.QWidget.__init__(self, parent)

(a reason to use super):

class NewQuery(QtGui.QWidget):
    def __init__(self, parent):
        super(NewQuery, self).__init__(parent)

But maybe you want inherit from QtGui.QDialog instead (that could be appropriate - hard to tell with the current context).

Also note that the indentation in your code example is wrong (a single space will work but 4 spaces or a single tab are considered nicer).

Answer 2

follow the advice that @ChristopheD gave you and try this instead

from PyQt4 import QtGui

class NewQuery(QtGui.QWidget):
    def __init__(self, parent=None):
        super(NewQuery, self).__init__(parent)
        self.setWindowTitle('Add New Query')
        grid = QtGui.QGridLayout()
        label = QtGui.QLabel('blah')
        grid.addWidget(label,0,0)
        self.setLayout(grid)
        self.resize(300,200)

app = QtGui.QApplication([])
mainform = NewQuery()
mainform.show()
newchildform = NewQuery()
newchildform.show()
app.exec_()