PyQt: Prevent Resize and Maximize in QDialog?

The above answers are just fine, besides, you could set maximum and mini widths and heights manually, like this:

myDialog = QDialog()
myDialog.setMaximumWidth(myDialog.width())
myDialog.setMaximumHeight(myDialog.height())

or in short, you could use maximumSize as:

myDialog.setMaximumSize()

Just as in the above code....

Use setFixedSize:

mydialog.setFixedSize(width, height)