ttk treeview: alternate row colors

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.

this is runnable without any extra modules... could mess with the code to make it work with your own.

from Tkinter import *
import ttk

class Test(Frame):

    def __init__(self):
        Frame.__init__(self)
        self.pack()
        self.listbox()
        self.buttons()

    def listbox(self):
        global new_customer_lb

        scrollbar = Scrollbar(self, orient="vertical")
        new_customer_lb = ttk.Treeview(self, columns=('ID','First Name','Last Name'))
        new_customer_lb['show']='headings'
        new_customer_lb.heading('#1', text= 'ID')
        new_customer_lb.column('#1', width=50, stretch=NO)
        new_customer_lb.heading('#2', text= 'First Name')
        new_customer_lb.column('#2', width=100, stretch=NO)
        new_customer_lb.heading('#3', text= 'Last Name')
        new_customer_lb.column('#3', width=100, stretch=NO)
        new_customer_lb.configure(yscroll = scrollbar.set, selectmode="browse")
        scrollbar.config(command=new_customer_lb.yview)
        new_customer_lb.pack()


    def buttons(self):
        load = Button(self, text='show customers', command=lambda:self.load_working_customers())
        test = Button(self, text='test new colors', command=lambda:self.test_colors())
        load.pack()
        test.pack()

    def load_working_customers(self):
        new_customer_lb.delete(*new_customer_lb.get_children())
        for a in range(0,10):            
            new_customer_lb.insert('','end', values=(a,'first','last'))

    def test_colors(self):
        new_customer_lb.delete(*new_customer_lb.get_children())                 

        new_customer_lb.tag_configure("evenrow",background='white',foreground='black')
        new_customer_lb.tag_configure("oddrow",background='black',foreground='white')
        for a in range(0,10):            
            if a % 2 == 0:
                new_customer_lb.insert('','end', values=(a,'first','last'), tags=('evenrow',))
            if a % 2 != 0:
                new_customer_lb.insert('','end', values=(a,'first','last'), tags=('oddrow',))

root = Tk()
app = Test()
app.mainloop()

I had this same issue a few months ago.

From the tk docs:

You can assign a list of tags to each item using the "tags" 
item configuration option (again, when creating the item or later on).

Tag configuration options can then be specified, which will then 
apply to all items having that tag.

Basically, you apply one tag to all of the odd-numbered rows, a different tag to each of the even-numbered rows, and then configure the tags.

---

When you create the items inside the treeview, add tags to them:

tree.insert('', 'end', text = 'your text', tags = ('oddrow',))

This code creates an element in tree, and the tags argument assigns the tag 'oddrow' to the element.

Once you've created all your elements with 'oddrow' and 'evenrow' tags, you can color the tags:

tree.tag_configure('oddrow', background='orange')
tree.tag_configure('evenrow', background='purple')