Question

I would like to do something like this in one source file, QT.py:

import sys
import PyQt4

sys.modules["Qt"] = PyQt4

Then import this file in the other source files, and use it like this:

import QT
from Qt.QtCore import *

So I can change from PyQt4 to PySide in QT.py without touching all the source files (with a possibly ugly sed script)
These modules are mostly API compatibile and I would like to test them both. Is there an easy way to do this? (Because the ways I tried are not working)

Maybe the I need imp module, but it seems too low level.

Any ideas?

Answer 1

update: Figured out method more in line with your requirements:

You can structure your pseudo-module as:

Qt/
Qt/__init__.py
Qt/QtCore/__init__.py
Qt/QtGui/__init__.py

Where Qt/__init__.py is:

import QtCore, QtGui

Qt/QtCore/__init__.py is:

from PyQt4.QtCore import *

Qt/QtGui/__init__.py is:

from PyQt4.QtGui import *

Then, in your code, you can reference it as follows:

import sys
from Qt import QtGui
app = QtGui.QApplication(sys.argv)

from Qt.QtGui import *

window = QWidget()
window.show()

app.exec_()

I highly recommend against using from Qt.QtGui import * in your code as importing everything is considered bad form in Python since you lose all namespaces in the process.

update:
I like Ryan’s suggestion of conditional imports. I’d recommend combining that into the above code. For example:

Qt/QtGui/__init__.py:

import sys
if '--PyQt4' in sys.argv:
    from PyQt4.QtGui import *
else:
    from PySide.QtGui import *