ttk treeview: alternate row colors

Question

How can I set a style for treeview widgets so that alternate rows have different background colors, for example, rows 1,3,5 have white backgrounds and rows 2,4,

Answer 1

I realise this is an old question but just for the record configuring the tags just after creating the tree (i.e. when no items have yet been added to it) also works. As items get inserted later on they will be given the background colour appropriate to their 'oddrow' or 'evenrow' tag.