Python - example [FB:learnpython.org]

#
# https://www.facebook.com/groups/learnpython.org/permalink/1213762838688331/
#

import tkinter as tk
import re

# --- constants ---
    # empty
# --- classes ---
    # empty
# --- functions ---

def my_function():
    # use entry_name.get() to get text

    save_file = open("AlanFile.txt","w")

    # ---

    word_list = re.split('\W+', text_entry.get(), flags=re.U)

    if word_list and word_list[0] == '':
        word_list = word_list[1:]
    if word_list and word_list[-1] == '':
        word_list = word_list[:-1]

    for word in words_entry.get().split():
        # I use `enumerate(..., 1) so I don't need `i+1` in other lines
        indexes = [i for i, x in enumerate(word_list, 1) if x==word]

        result_text.insert('end', "%s: %s\n" % (word, indexes))
        save_file.write("%s: %s\n" % (word, indexes))

    # ---

    words = []
    for index in indexes_entry.get().split():
        words.append(word_list[int(index)-1])

    text = " ".join(words)

    result_text.insert('end', text)
    save_file.write(text)

    # ---

    result_text.insert('end', '\n-------\n')

    save_file.close()

# --- main ---

root = tk.Tk()

tk.Label(root, text="Enter text > ").grid(row=0, column=0, sticky='E')
text_entry = tk.Entry(root)
text_entry.grid(row=0, column=1, sticky='WE')

tk.Label(root, text="Enter words > ").grid(row=1, column=0, sticky='E')
words_entry = tk.Entry(root)
words_entry.grid(row=1, column=1, sticky='WE')

tk.Label(root, text="Enter indexes > ").grid(row=2, column=0, sticky='E')
indexes_entry = tk.Entry(root)
indexes_entry.grid(row=2, column=1, sticky='WE')

tk.Button(root, text="Run", command=my_function).grid(row=3, column=1)

result_text = tk.Text(root)
result_text.grid(row=4, columnspan=2)

# I set some text for test

text_entry.insert(0, 'hello world of python')
words_entry.insert(0, 'world python')
indexes_entry.insert(0, '2 1')

# run program (start "the engine")

root.mainloop()