How do I use permutation to find all possible words from an input?

Question

I am doing a project for my programming class, here are the 5 things that I am working towards. Thanks for your help!

1. list of valid words will be provided in a words.txt
2. ask for input that only accepts a combination of 2-8 letters
3. Ex. input would be "polo"
4. Find all possible valid words of this input from inside words.txt

5. Possible outcomes, "poo" "pool" "loop" "polo"

   import random
   import itertools
   
   file_name='words.txt'
   DEBUG=True
   
   def load_words():
       try:
           f=open(file_name,'r')
           str1=f.read()
           f.close()
       except:
           print('Problem opening the file',file_name)
       list1=[]
       list1=str1.split()
       if DEBUG:
           length=len(list1)
           print('Number of words is',length)
           print(list1[0],list1[length//2],list1[-1])
           for i in range(10):
               print(list1[random.randint(1,length)])
       return(list1)
   
   def is_valid(str1,list1):
       valid=False
       count=0
       if str1 in list1:
           valid=True
       return valid
   
   def generate(letters):
       print(len(letters))
       count=1
       answers=[]
       for length in range(2,len(letters)+1):
           for x in itertools.permutations(letters,length):
               word=''
               for let in x:
                   word+=let
               print(word)
               if is_valid(word):
                   answers.append(word)
               count+=1   
           print(count,x)
           return(answers)
   
   def main():
       words=load_words()
       generate('abcde')
       guess=input('Check a word')
       if is_valid(guess.upper(),words):
           print(guess,'is a real word')
       else:
           print(guess,'is not a real word')
   
   main()
   

Answer 1

as far as the error is concerned print(list1[random].randint(1,length)) should be changed to print(list1[random.randint(1,length)])