Autocomplete ComboBox in Python-Tkinter

Prerequisites: Python GUI – tkinter

The Listbox widget is used to display a list of items from which a user can select a number of items. But have you ever wondered, how to return the list of possible results when a key is pressed? Let’s see the following approach towards the same.

Working of Program

• List consisting of words is initialized.
• Entry box and Listbox are created and are added to the root window.
• Bind function is used for event handling. Key release event is handled for an Entry field.
• When any key is pressed in the Entry, checkkey() function is called.
• checkkey() function then compares the entered string with existing list keywords and populates Listbox with matching keywords.
• Then this data is sent to update function which then updates the Listbox.

Below is the approach.

from tkinter import *


# Function for checking the
# key pressed and updating
# the listbox
def checkkey(event):

    value = event.widget.get()
    print(value)

    # get data from l
    if value == '':
        data = l
    else:
        data = []
        for item in l:
            if value.lower() in item.lower():
                data.append(item)

    # update data in listbox
    update(data)


def update(data):

    # clear previous data
    lb.delete(0, 'end')

    # put new data
    for item in data:
        lb.insert('end', item)


# Driver code
l = ('C','C++','Java',
     'Python','Perl',
     'PHP','ASP','JS' )

root = Tk()

#creating text box
e = Entry(root)
e.pack()
e.bind('<KeyRelease>', checkkey)

#creating list box
lb = Listbox(root)
lb.pack()
update(l)

root.mainloop()

Output: