KeyError в / рекомендует / в комбинированных_функциях

Question

почему я получаю эту ошибку в комбинированных функциях, почему она появляется и показывает, почему df или локальные переменные присвоены

def recommendation(Movie):
            Movie = Movie.lower()
            try:
                df.head()
                cosine_sim.shape
            except:
                cosine_sim = recommender_sim()
            if Movie not in df['title'].unique():
                return('Search for another Movies')
            else:
                indices = pd.Series(df.index, index=df['title'])
                # Get the index of the movie that matches the title
                idx = indices[title]

            # Get the pairwsie similarity scores of all movies with that movie
                sim_scores = list(enumerate(cosine_sim[idx]))

            # Sort the movies based on the similarity scores
                sim_scores = sorted(sim_scores, key=lambda x: x[1], reverse=True)

            # Get the scores of the 10 most similar movies
                sim_scores = sim_scores[1:11]

                sim_scores = []
                for i in range(len(sim_scores)):
                    movie_indices = sim_scores[i][0]
                    sim_scores.append(df['title'][movie_indices])
                return sim_scores


        def recommend(request):
            if request.method == 'GET':

                movie = request.GET['movie']
                movies = recommendation(movie)
                movie = movie.upper()
                if type(movies) == type('string'):
                    return HttpResponse('recommend.html', movie=movie, movies=movies, t='s')
                else:
                    return HttpResponse('recommend.html', movie=movie, movies=movies, t='sim_scores')
            return render(request, 'recommend.html')