Tkinter - Cómo crear un cuadro combinado con autocompletado

Question

¿Es posible crear un cuadro combinado que se actualice con el elemento más cercano en su lista mientras escribe en él?

Por ejemplo:

A = ttk.Combobox() 
A['values'] = ['Chris', 'Jane', 'Ben', 'Megan'] 

A continuación, escriba "Chr" en el cuadro combinado, lo quiero, para rellenar automáticamente "Chris".

Answer 1

El wiki de tkinter contiene code para un cuadro de texto de autocompletado, pero como quiere un cuadro combinado, puede usar el código this (está buscando AutocompleteCombobox).

---

""" 
tkentrycomplete.py 

A Tkinter widget that features autocompletion. 

Created by Mitja Martini on 2008-11-29. 
Updated by Russell Adams, 2011/01/24 to support Python 3 and Combobox. 
Updated by Dominic Kexel to use Tkinter and ttk instead of tkinter and tkinter.ttk 
    Licensed same as original (not specified?), or public domain, whichever is less restrictive. 
""" 
import sys 
import os 
import Tkinter 
import ttk 

__version__ = "1.1" 

# I may have broken the unicode... 
Tkinter_umlauts=['odiaeresis', 'adiaeresis', 'udiaeresis', 'Odiaeresis', 'Adiaeresis', 'Udiaeresis', 'ssharp'] 

class AutocompleteEntry(Tkinter.Entry): 
     """ 
     Subclass of Tkinter.Entry that features autocompletion. 

     To enable autocompletion use set_completion_list(list) to define 
     a list of possible strings to hit. 
     To cycle through hits use down and up arrow keys. 
     """ 
     def set_completion_list(self, completion_list): 
       self._completion_list = sorted(completion_list, key=str.lower) # Work with a sorted list 
       self._hits = [] 
       self._hit_index = 0 
       self.position = 0 
       self.bind('<KeyRelease>', self.handle_keyrelease) 

     def autocomplete(self, delta=0): 
       """autocomplete the Entry, delta may be 0/1/-1 to cycle through possible hits""" 
       if delta: # need to delete selection otherwise we would fix the current position 
         self.delete(self.position, Tkinter.END) 
       else: # set position to end so selection starts where textentry ended 
         self.position = len(self.get()) 
       # collect hits 
       _hits = [] 
       for element in self._completion_list: 
         if element.lower().startswith(self.get().lower()): # Match case-insensitively 
           _hits.append(element) 
       # if we have a new hit list, keep this in mind 
       if _hits != self._hits: 
         self._hit_index = 0 
         self._hits=_hits 
       # only allow cycling if we are in a known hit list 
       if _hits == self._hits and self._hits: 
         self._hit_index = (self._hit_index + delta) % len(self._hits) 
       # now finally perform the auto completion 
       if self._hits: 
         self.delete(0,Tkinter.END) 
         self.insert(0,self._hits[self._hit_index]) 
         self.select_range(self.position,Tkinter.END) 

     def handle_keyrelease(self, event): 
       """event handler for the keyrelease event on this widget""" 
       if event.keysym == "BackSpace": 
         self.delete(self.index(Tkinter.INSERT), Tkinter.END) 
         self.position = self.index(Tkinter.END) 
       if event.keysym == "Left": 
         if self.position < self.index(Tkinter.END): # delete the selection 
           self.delete(self.position, Tkinter.END) 
         else: 
           self.position = self.position-1 # delete one character 
           self.delete(self.position, Tkinter.END) 
       if event.keysym == "Right": 
         self.position = self.index(Tkinter.END) # go to end (no selection) 
       if event.keysym == "Down": 
         self.autocomplete(1) # cycle to next hit 
       if event.keysym == "Up": 
         self.autocomplete(-1) # cycle to previous hit 
       if len(event.keysym) == 1 or event.keysym in Tkinter_umlauts: 
         self.autocomplete() 

class AutocompleteCombobox(ttk.Combobox): 

     def set_completion_list(self, completion_list): 
       """Use our completion list as our drop down selection menu, arrows move through menu.""" 
       self._completion_list = sorted(completion_list, key=str.lower) # Work with a sorted list 
       self._hits = [] 
       self._hit_index = 0 
       self.position = 0 
       self.bind('<KeyRelease>', self.handle_keyrelease) 
       self['values'] = self._completion_list # Setup our popup menu 

     def autocomplete(self, delta=0): 
       """autocomplete the Combobox, delta may be 0/1/-1 to cycle through possible hits""" 
       if delta: # need to delete selection otherwise we would fix the current position 
         self.delete(self.position, Tkinter.END) 
       else: # set position to end so selection starts where textentry ended 
         self.position = len(self.get()) 
       # collect hits 
       _hits = [] 
       for element in self._completion_list: 
         if element.lower().startswith(self.get().lower()): # Match case insensitively 
           _hits.append(element) 
       # if we have a new hit list, keep this in mind 
       if _hits != self._hits: 
         self._hit_index = 0 
         self._hits=_hits 
       # only allow cycling if we are in a known hit list 
       if _hits == self._hits and self._hits: 
         self._hit_index = (self._hit_index + delta) % len(self._hits) 
       # now finally perform the auto completion 
       if self._hits: 
         self.delete(0,Tkinter.END) 
         self.insert(0,self._hits[self._hit_index]) 
         self.select_range(self.position,Tkinter.END) 

     def handle_keyrelease(self, event): 
       """event handler for the keyrelease event on this widget""" 
       if event.keysym == "BackSpace": 
         self.delete(self.index(Tkinter.INSERT), Tkinter.END) 
         self.position = self.index(Tkinter.END) 
       if event.keysym == "Left": 
         if self.position < self.index(Tkinter.END): # delete the selection 
           self.delete(self.position, Tkinter.END) 
         else: 
           self.position = self.position-1 # delete one character 
           self.delete(self.position, Tkinter.END) 
       if event.keysym == "Right": 
         self.position = self.index(Tkinter.END) # go to end (no selection) 
       if len(event.keysym) == 1: 
         self.autocomplete() 
       # No need for up/down, we'll jump to the popup 
       # list at the position of the autocompletion 

def test(test_list): 
     """Run a mini application to test the AutocompleteEntry Widget.""" 
     root = Tkinter.Tk(className=' AutocompleteEntry demo') 
     entry = AutocompleteEntry(root) 
     entry.set_completion_list(test_list) 
     entry.pack() 
     entry.focus_set() 
     combo = AutocompleteCombobox(root) 
     combo.set_completion_list(test_list) 
     combo.pack() 
     combo.focus_set() 
     # I used a tiling WM with no controls, added a shortcut to quit 
     root.bind('<Control-Q>', lambda event=None: root.destroy()) 
     root.bind('<Control-q>', lambda event=None: root.destroy()) 
     root.mainloop() 

if __name__ == '__main__': 
     test_list = ('apple', 'banana', 'CranBerry', 'dogwood', 'alpha', 'Acorn', 'Anise') 
     test(test_list) 

Answer 2

El AutoCompleteComboBox es una verdadera belleza de hecho, la respuesta anterior se refiere a ir a buscar en una lista de valores que figuran en el código Python. Estoy mejorando la respuesta para incluir datos obtenidos de SQLite y se muestran en un cuadro combinado:

if __name__ == '__main__': 
     #test_list = ('apple', 'banana', 'CranBerry', 'dogwood', 'alpha', 'Acorn', 'Anise', 'crannotberry') 
     #test(test_list) 

     connection = sqlite3.connect('my_sqliteDB') 
     cur = connection.cursor() 
     cur.execute("select stock_item_name from inventory") 
     sqloutput = cur.fetchall() #This contains the SQL output in format [(u'data1',), (u'data2',), (u'data3',)] 
     sqloutput_2 = [item[0] for item in sqloutput] #This is manipulated to the format [u'data1',u'data2',u'data3'] 
     test_list = tuple(map(str, sqloutput_2)) #This will remove the unicode data and final format [data1,data2,data3] 
     test(test_list) #The final format works with values in DB.