Changing the length of a table dynamically in python

Question

I have written the following python program to choose a variable number of shapes(n=3,8,5) from a list and make and show a table with (n+1=4,9,6) upon selection of three different keys from a combobox dropdown list.The problem is that the number of table columns would not change with the selected keys and is fixed at its initial setting but the table contents are updated for these fixed columns.Your Kind suggestions for displaying a variable length table is much appreciated.

from traits.api import HasTraits, Instance, List, Str 
from traitsui.api import Item, View, VGroup, EnumEditor,TableEditor, ObjectColumn

keys = ["key1", "key2", "key3"]
ph_dict={}
ph_dict["key1"] = ["A1","A2","A3"]
ph_dict["key2"] = ["B1", "B2", "B3", "B4",  "B5", "B6", "B7", "B8"]
ph_dict["key3"] = ["C1", "C2","C3", "C4", "C5"]

shapes = ["square", "circle","inverted_triangle", "diamond", "dot", "cross", "plus",       
"pixel"] 


class ShapeTable(HasTraits):
    pass


class DynamicTable(HasTraits):

    Shape = Str
    Shapedropdownlist = List(Str)
    shapes_name = List(Str)

    shape_table = List(Instance(ShapeTable))
    shape_columns = [ObjectColumn(name="Name")]
    shape_columns.append(ObjectColumn(name="Value"))    
    shape_table_editor=TableEditor(columns=shape_columns,
        deletable = True,
        sortable = False,
        sort_model = False,
        show_lines = True,
        line_color = "black",
        editable= False,
        show_column_labels = False)

    traits_view = View(VGroup(
                      Item('Shape',editor=EnumEditor(name='Shapedropdownlist',),),
                      Item( 'shape_table',editor=shape_table_editor,show_label=False,
                             width=0.3, padding=0)),

                       width=500, height=200, resizable=True,
                       title = "Dynamic table trait"
                       )


    def __init__(self):
        super(DynamicTable, self).__init__()

        self.shapes_name = ph_dict[keys[1]]

        self.shape_table_editor.columns = [ObjectColumn(name='name')]
        for i in range(len(shapes)):
            self.shape_table_editor.columns.append(ObjectColumn(name=shapes[i]))

        self.Shapedropdownlist = keys
        self.Shape = keys[2]
        self._updateShapeTable()

        return

    def _Shape_changed(self, selectedValue):
        self.pshape = selectedValue 
        self.shapes_name = ph_dict[self.pshape]
        self._updateShapeTable()


    def _updateShapeTable(self):
        del(self.shape_table)
        self.shape_table_editor.columns = [ObjectColumn(name='name')]
        for i in range(len(self.shapes_name)):
            print(i,len(self.shapes_name))
            self.shape_table_editor.columns.append(ObjectColumn(name=shapes[i]))
        data = ShapeTable()    
        data.name = "Name"

        for i in range(len(self.shapes_name)):
            print(i,len(self.shapes_name))
            exec('data.'+shapes[i]+'="'+self.shapes_name[i]+'"')
        self.shape_table.append(data)        

        data = ShapeTable()
        data.name = "Shape"
        for i in range(len(self.shapes_name)):
            exec('data.'+shapes[i]+'="'+shapes[i]+'"')
        self.shape_table.append(data)


if __name__ == "__main__": 

    f1 = DynamicTable()
    f1.configure_traits()

NaMarPi · Answer 1 · 2013-11-04T14:26:10.737

You can use the columns_name parameter instead of the columns parameter when specifying the columns of the TableEditor.

In the _updateShapeTable method you should initialize the shape_columns context attribute, than append the columns to it.

from traits.api import HasTraits, Instance, List, Str 
from traitsui.api import Item, View, VGroup, EnumEditor,TableEditor, ObjectColumn

keys = ["key1", "key2", "key3"]
ph_dict={}
ph_dict["key1"] = ["A1","A2","A3"]
ph_dict["key2"] = ["B1", "B2", "B3", "B4",  "B5", "B6", "B7", "B8"]
ph_dict["key3"] = ["C1", "C2","C3", "C4", "C5"]

shapes = ["square", "circle","inverted_triangle", "diamond", "dot", "cross", "plus", "pixel"] 


class ShapeTable(HasTraits):
    pass


class DynamicTable(HasTraits):

    Shape = Str
    Shapedropdownlist = List(Str)
    shapes_name = List(Str)

    shape_table = List(Instance(ShapeTable))
    shape_columns = List(Instance(ObjectColumn()))  
    shape_table_editor=TableEditor(columns_name='shape_columns',
        deletable = True,
        sortable = False,
        sort_model = False,
        show_lines = True,
        line_color = "black",
        editable= False,
        show_column_labels = False)

    traits_view = View(VGroup(
                    Item('Shape',editor=EnumEditor(name='Shapedropdownlist',),),
                    Item( 'shape_table',editor=shape_table_editor,show_label=False,
                            width=0.3, padding=0)),

                    width=500, height=200, resizable=True,
                    title = "Dynamic table trait"
                    )


    def __init__(self):
        super(DynamicTable, self).__init__()

        self.shapes_name = ph_dict[keys[1]]

        self.shape_table_editor.columns = [ObjectColumn(name='name')]

        self.Shapedropdownlist = keys
        self.Shape = keys[2]
        self._updateShapeTable()

        return


    def _Shape_changed(self, selectedValue):
        self.pshape = selectedValue 
        self.shapes_name = ph_dict[self.pshape]
        self._updateShapeTable()


    def _updateShapeTable(self):
        del(self.shape_table)
        self.shape_columns = [ObjectColumn(name='name')]
        for i in range(len(self.shapes_name)):
            print(i,len(self.shapes_name))
            self.shape_columns.append(ObjectColumn(name=shapes[i]))
        data = ShapeTable()    
        data.name = "Name"

        for i in range(len(self.shapes_name)):
            print(i,len(self.shapes_name))
            exec('data.'+shapes[i]+'="'+self.shapes_name[i]+'"')
        self.shape_table.append(data)        

        data = ShapeTable()
        data.name = "Shape"
        for i in range(len(self.shapes_name)):
            exec('data.'+shapes[i]+'="'+shapes[i]+'"')
        self.shape_table.append(data)


if __name__ == "__main__": 

    f1 = DynamicTable()
    f1.configure_traits()

Changing the length of a table dynamically in python

1 Answers1