Is lambda "better"?

'''
Different ways to doSomething(row, column) based on the clicked button
'''


class GuiBase(QtWidgets.QWidget):
    def doSomething(self, row, column):
        print(row, column)

'''
Using a "matrix" and self.sender()
'''


class GuiDefGrid(GuiBase):
    def __init__(self):
        super().__init__()
        layout = QtWidgets.QGridLayout(self)
        self.grid = []
        for row in range(4):
            rowList = []
            self.grid.append(rowList)
            for column in range(4):
                button = QtWidgets.QPushButton('{} {}'.format(row, column))
                layout.addWidget(button, row, column)
                rowList.append(button)
                button.clicked.connect(self.doSomethingFromButton)

    def doSomethingFromButton(self):
        sender = self.sender()
        for row, rowList in enumerate(self.grid):
            for column, button in enumerate(rowList):
                if button == sender:
                    self.doSomething(row, column)
                    break


'''
Setting a custom object attribute, also with sender()
'''


class GuiDefAttrib(GuiBase):
    def __init__(self):
        super().__init__()
        layout = QtWidgets.QGridLayout(self)
        for row in range(4):
            for column in range(4):
                button = QtWidgets.QPushButton('{} {}'.format(row, column))
                layout.addWidget(button, row, column)
                button.clicked.connect(self.doSomethingFromButton)
                button.coords = (row, column)

    def doSomethingFromButton(self):
        sender = self.sender()
        self.doSomething(*sender.coords)


class GuiLambda(GuiBase):
    def __init__(self):
        super().__init__()
        layout = QtWidgets.QGridLayout(self)
        for row in range(4):
            for column in range(4):
                button = QtWidgets.QPushButton('{} {}'.format(row, column))
                layout.addWidget(button, row, column)
                button.clicked.connect(lambda _, r=row, c=column: self.doSomething(r, c))

But my point is that you can just do the following:

class GuiLambda(GuiBase):
    def __init__(self):
        super().__init__()
        layout = QtWidgets.QGridLayout(self)
        for row in range(4):
            for column in range(4):
                button = QtWidgets.QPushButton('{} {}'.format(row, column))
                layout.addWidget(button, row, column)
                def _click_handler(_, r=row, c=column): return self.doSomething(r, c)
                button.clicked.connect(_click_handler)

And it does the same thing.

lambda x,y: x*y

is essentially sugar for:

def some_unique_name(x, y): return x*y; del some_unique_name

Most of the time, you don't care, because you are in some loop in some local scope, so the name doesn't matter.

Yes, you're right, that's another option.
Nonetheless I don't think that's an improvement over lambda (but I realize that it's also a matter of preference and habit, amongst other things), since in similar cases (and others I was referring to in my comment) one doesn't really care about the function name as you also pointed out, and the syntax is usually smaller and easier to write/read.
Plus, it takes half the lines :-P