Tkinter - Adding multiple columns to a Treeview

Question

I want to add three columns to my Treeview and name them 'Varenavn','Antall','Best før'. I tried the following:

self.tree = ttk.Treeview (height = 10, columns = 3)  
self.tree.grid (row = 4, column = 0, columnspan = 2)  
self.tree.heading ('#0', text = 'Varenavn', anchor = W)  
self.tree.heading ('#1', text = 'Antall', anchor = W)  
self.tree.heading ('#2', text = 'Best før', anchor = W) 

But I am getting:

 _tkinter.TclError: Column #2 out of range.

If I change the last bit of code to:

self.tree.heading ('#1', text = 'Best før', anchor = W) 

The code runs fine, but overwrites 'Antall' to 'Best før' in the second column.

Any ideas would be greatly appreciated!

Answer 1

The value you give to the columns= argument isn't doing what you expect it to do.

From the New Mexico Tech Tkinter reference:

columns

A sequence of column identifier strings. These strings are used internally to identify the columns within the widget. The icon column, whose identifier is always '#0', contains the collapse/expand icons and is always the first column.

The columns you specify with the columns argument are in addition to the icon column.

For example, if you specified columns=('Name', 'Size'), three columns would appear in the widget: first the icon column, then two more columns whose internal identifiers are 'Name' and 'Size'.

So instead of a number, you should give it a tuple of names for the columns you want to create, and you should give one less than the total number of columns you want, since the first is always '#0'.

---

To explain the error you're getting, when you use columns = 3 this gives the same result as using columns = ('3') would; you're actually only creating one column next to the '#0' column, which can be identified by either '#1' or '3'. When you try to access column '#2' you get an out of range error because there are only two columns.

Answer 2

For example you need to specify

self.tablex=ttk.Treeview(heigh=10,columns=("#0","#1","#2","#3"))

and later

self.tablex.heading('#0',text='Text0')
self.tablex.heading('#1',text='Text1')
self.tablex.heading('#2',text='Text2')
self.tablex.heading('#3',text='Text3')

Answer 3

There are multiple ways to add columns.

Using a for-loop:

import tkinter as tk
from tkinter import ttk

root = tk.Tk()
tree = ttk.Treeview(root,columns=())
tree.pack(fill='x')

for i in range(5):
    param = tree['columns']+(f'#{i+1}',)
    tree.configure(columns=param)
    
for i in range(5):
    tree.heading(column=f'#{i+1}',text=f'text{i+1}',anchor='w')
    tree.column(column=f'#{i+1}', width=150,minwidth=50,stretch=False)


root.mainloop()

Using a list:

import tkinter as tk
from tkinter import ttk

cols = ['one','two','three','four','five']

root = tk.Tk()
tree = ttk.Treeview(root,columns=cols)
tree.pack(fill='x')
    
for i in cols:
    tree.heading(column=f'{i}',text=f'{i}',anchor='w')
    tree.column(column=f'{i}', width=150,minwidth=50,stretch=False)


root.mainloop()

manually:

import tkinter as tk
from tkinter import ttk


root = tk.Tk()
tree = ttk.Treeview(root,columns=('one','two','three','four','five'))
tree.pack(fill='x')

    
for i in tree['columns']:
    tree.heading(column=f'{i}',text=f'{i}',anchor='w')
    tree.column(column=f'{i}', width=150,minwidth=50,stretch=False)


root.mainloop()

generic:

import tkinter as tk
from tkinter import ttk


root = tk.Tk()
tree = ttk.Treeview(root,columns=tuple(f"{i}" for i in range(5)))
tree.pack(fill='x')
    
for i in tree['columns']:
    tree.heading(column=f'{i}',text=f'{i}',anchor='w')
    tree.column(column=f'{i}', width=150,minwidth=50,stretch=False)


root.mainloop()