Python Qt: Qprinter not defined

I am trying to put the printer to run the output from an html document.

Here is a small function to do that:

def callPrinterHtml(self,document):
    self.printer = QPrinter()
    self.printer.setPageSize(QPrinter.Letter)

    dialog = QPrintDialog(self.printer, self)
    if dialog.exec_():
     开发者_开发百科   document.print_(self.printer)

However the message pops up:

self.printer = QPrinter()
NameError: global name 'QPrinter' is not defined

The printer definition is clearly inside the function. So, what am I missing here?

All comments and suggestions are highly appreciated.

---

1. Did you import the module that contains QPrinter? using an import directive?

2. Is the module containing QPrinter in your python path?