Python Qt Image Viewer Application with Rotate Feature Included

I have been building this Image Viewer in Python and I am now up to the point where it is already coming in useful.

I can browse back and forth, select in finder/file manager, and today I added the ability to rotate the picture on the screen.

Get the full code here in this Gist

Adding Rotate

The key additions were the button ...

rotate = QPushButton("Rotate", window)
rotate.clicked.connect(rotate_picture)
rotate.setShortcut(QtGui.QKeySequence.MoveToPreviousLine)
rotate.move(380, 0)

and this function ....

# rotate 90
def rotate_picture():
    global window, file, files, index, label
    file = files[index]
    picture = label.pixmap()
    transform = QTransform().rotate(90)
    picture = picture.transformed(transform)
    label.setPixmap(picture)
    label.setGeometry(QtCore.QRect(10, 40, picture.width(), picture.height()))
    window.resize(picture.width()+20, picture.height()+100)
    window.setWindowTitle(file)
    window.show()

Where before we have been using the filename to load the image from the file system, if I did that we would simply rotate 90 degrees then seem to stop working, because every rotate click/press would rotate the original 90 degrees.

Instead we take the existing label image and rotate that.

picture = label.pixmap()

The rest is easy, we create a 90 degree transform, apply it, then set the label image to this transformed version.