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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _drag_col(self, event):
 """Continue dragging a column"""

        x = self._dx + event.x  # get dragged column new left x coordinate
        self._visual_drag.place_configure(x=x)  # update column preview position
        # if one border of the dragged column is beyon the middle of the
        # neighboring column, swap them
        if (self._dragged_col_neighbor_widths[0] is not None and
               x < self._dragged_col_x - self._dragged_col_neighbor_widths[0] / 2):
            self._swap_columns('left')
        elif (self._dragged_col_neighbor_widths[1] is not None and
               x > self._dragged_col_x + self._dragged_col_neighbor_widths[1] / 2):
            self._swap_columns('right')
        # horizontal scrolling if the cursor reaches the side of the table
        if x < 0 and self.xview()[0] > 0:
            # scroll left and update dragged column x coordinate
            self.xview_scroll(-10, 'units')
            self._dragged_col_x += 10
        elif x + self._dragged_col_width / 2 > self.winfo_width() and self.xview()[1] < 1:
            # scroll right and update dragged column x coordinate
            self.xview_scroll(10, 'units')
            self._dragged_col_x -= 10