A tkinter code to make auto-filling entries.

AutofillEntry.py

from tkinter import *
import re

lista = ['i', 'went', 'through', 'executemany()', 'as', 'well', 'but', 'sorry', 'to', 'say', 'I', 'am', 'quite', 'new', 'to', 'both', 'python', 'and', 'sqlite.', 'My', 'doubt', 'is', 'like', 'if', 'I', 'have,', 'say', 'a', 'list', 'of', 'filenames', 'which', 'I', 'have', 'prepared', 'by', 'appending', 'values', 'inside', 'a', 'list', 'object,', 'then', 'how', 'can', 'I', 'use', 'it', 'with', 'executeMany..', 'is', 'it', 'like', 'simply', 'passing', 'the', 'list', 'object', '(say', 'fileList)', 'to', 'executemany()?..', 'Any', 'code', 'snippet', 'would', 'be', 'really', 'appreciated..', 'thanks']
#Some Random crap, don't judge

class AutocompleteEntry(Entry):
    def __init__(self, *args, **kwargs):

        Entry.__init__(self, *args, **kwargs)
        self.lista = kwargs['lis']
        self.var = self["textvariable"]
        if self.var == '':
            self.var = self["textvariable"] = StringVar()

        self.var.trace('w', self.changed)
        self.bind("<Right>", self.selection)
        self.bind("<Up>", self.up)
        self.bind("<Down>", self.down)
        self.bind("<Return>",self.selection)

        self.lb_up = False

    def changed(self, name, index, mode):
        if self.var.get() == '':
            try:
                self.lb.destroy()
                self.lb_up = False
            except AttributeError:
                pass
        else:
            words = self.comparison()
            if words:
                if not self.lb_up:
                    self.lb = Listbox()
                    self.lb.bind("<Double-Button-1>", self.selection)
                    self.lb.bind("<Right>", self.selection)
                    self.lb.place(x=self.winfo_x(), y=self.winfo_y() + self.winfo_height())
                    self.lb_up = True

                self.lb.delete(0, END)
                for w in words:
                    self.lb.insert(END, w)
            else:
                if self.lb_up:
                    self.lb.destroy()
                    self.lb_up = False

    def selection(self, event):
        if self.lb_up:
            self.var.set(self.lb.get(ACTIVE))
            self.lb.destroy()
            self.lb_up = False
            self.icursor(END)

    def up(self, event):

        if self.lb_up:
            if self.lb.curselection() == ():
                index = '0'
            else:
                index = self.lb.curselection()[0]
            if index != '0':
                self.lb.selection_clear(first=index)
                index = str(int(index) - 1)
                self.lb.selection_set(first=index)
                self.lb.activate(index)

    def down(self, event):

        if self.lb_up:
            if self.lb.curselection() == ():
                index = '-1'
            else:
                index = self.lb.curselection()[0]
            if index != END:
                self.lb.selection_clear(first=index)
                index = str(int(index)+1)
                self.lb.selection_set(first=index)
                self.lb.activate(index)

    def comparison(self):
        pattern = re.compile('.*' + str(self.var.get()).lower() + '.*')
        print(pattern)
        return [w for w in self.lista if re.match(pattern, str.lower(w))]


if __name__ == '__main__':
    root = Tk()
    root.tk_setPalette(background='#ffffff')

    entry = AutocompleteEntry(lis=lista, root)
    entry.grid(row=0, column=0)
    Button(text='nothing').grid(row=1, column=0)
    Button(text='nothing').grid(row=2, column=0)
    Button(text='nothing').grid(row=3, column=0)

    root.mainloop()