Building a text editor with PyQt: Part 2 - Indent/Dedent Fix

def indent(self):
    # Grab the cursor
    cursor = self.text.textCursor()

    if cursor.hasSelection():
        # Store the current line/block number
        temp = cursor.blockNumber()
        direction = None
        diff = None

        # Determine cursor position relative to selection start/end
        # Move to opposite position
        # Set cursor movement direction
        # Calculate range of selection
        if cursor.position() == cursor.selectionStart():
            cursor.setPosition(cursor.selectionEnd())
            direction = QtGui.QTextCursor.Up
            diff = cursor.blockNumber() - temp
        elif cursor.position() == cursor.selectionEnd():
            cursor.setPosition(cursor.selectionStart())
            direction = QtGui.QTextCursor.Down
            diff = temp

        # Iterate over lines
        for n in range(diff + 1):
            # Move to start of each line
            cursor.movePosition(QtGui.QTextCursor.StartOfLine)
            # Insert tabbing
            cursor.insertText('\t')
            # And move to next line
            cursor.movePosition(direction)

    # If there is no selection just insert a tab
    else:
        cursor.insertText('\t')

def dedent(self):
    # Grab the cursor
    cursor = self.text.textCursor()

    if cursor.hasSelection():
        # Store the current line/block number
        temp = cursor.blockNumber()
        direction = None
        diff = None

        # Determine cursor position relative to selection start/end
        # Move to opposite position
        # Set cursor movement direction
        # Calculate range of selection
        if cursor.position() == cursor.selectionStart():
            cursor.setPosition(cursor.selectionEnd())
            direction = QtGui.QTextCursor.Up
            diff = cursor.blockNumber() - temp
        elif cursor.position() == cursor.selectionEnd():
            cursor.setPosition(cursor.selectionStart())
            direction = QtGui.QTextCursor.Down
            diff = temp

        # Iterate over lines
        for n in range(diff + 1):
            self.handleDedent(cursor)
            # Move up
            cursor.movePosition(direction)

    # If there is no selection just insert a tab
    else:
        self.handleDedent(cursor)