Python I cant retrive the random word from a list,,while loop doesnt work just got stucked at the beginning but there is no error

Question

import random
from words import words
import string

def getValidWord(words):
    selected=random.choice(words)
    while '-' or  ' ' in selected:
         selected=random.choice(words)
    return selected.upper()


def hang_tracker():
    
    word=getValidWord(words)
    Letters_word=set(word)
    a_to_z=set(string.ascii_uppercase)
    used_letters=set()
   
    while len(Letters_word)>0:
        
        print("You have used these letters:",' '.join(used_letters))
        #current word
        cur_word=[letter if letter in used_letters else '-' for letter in word]
        print("Current word:",' '.join(cur_word))
        user_letter=input("Guess a letter:").upper()
        if user_letter in a_to_z - used_letters:
           used_letters.add(user_letter)
           if user_letter in Letters_word:
              Letters_word.remove(user_letter)
        elif user_letter in used_letters:
            print(f'You have used {user_letter} letter before. Try again!')
        else:
            print("ınvalid character!")
        


hang_tracker()