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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 OnImport(self, event):
 """File import event handler"""


        # Get filepath from user

        wildcards = get_filetypes2wildcards(["csv", "txt"]).values()
        wildcard = "|".join(wildcards)

        message = _("Choose file to import.")
        style = wx.OPEN
        filepath, filterindex = \
            self.interfaces.get_filepath_findex_from_user(wildcard, message,
                                                          style)

        if filepath is None:
            return

        # Get generator of import data
        import_data = self.main_window.actions.import_file(filepath,
                                                           filterindex)

        if import_data is None:
            return

        # Paste import data to grid
        grid = self.main_window.grid
        tl_cell = grid.GetGridCursorRow(), grid.GetGridCursorCol()

        grid.actions.paste(tl_cell, import_data)

        self.main_window.grid.ForceRefresh()