How do I update the data associated with a QListWidgetItem from the QListWidget in PyQt?

Question

I have a QListWidget that has 10 QListWidgetItems . When each of those QListWidgetItems is created I do something like this:

item = QtGui.QListWidgetItem("Text to Show")
item.setData(36, "A specific value that is used later")
self.ui.my_list.addItem(item)

Now, later in the application, after a user clicks a button, I want to update the text "A specific value that is used later", for the item that is selected. I have attempted to do this

ndx = self.ui.my_list.currentRow()
self.ui.my_list.item(ndx).setData(36, "Updated!")

The problem is, this doesn't work. It doesn't throw any errors, but the data is just gone. In my button press signal I have this code to see the value before and after the reassignment:

ndx = self.ui.my_list.currentRow()   
print "Before:", self.ui.my_list.item(ndx).data(36).toPyObject()
self.ui.my_list.item(ndx).setData(36, "Updated!")
print "After:", self.ui.my_list.item(ndx).data(36).toPyObject()

This outputs:

Before: A specific value that is used later
After:

How can I properly change the data so that it is saved back to the QListWidgetItem ?

Answer 1

You may want to check that the role value your using is a valid user role, otherwise it may be altered internally. I write in c++, but I use the QListWidget and QListWidgetItem(s) frequently, and this was a problem I encountered early on. I imagen that the functionality is similar regardless of the language. According to the documentation here , the first user role that can be used is 0x0010. So to tie it to your example, you might try the following:

item.setData(0x0010, "A specific value that is used later")

For additional item roles you would use 0x0011, 0x0012, 0x0013, etc.