I am unable to resolve the error with the below code:
The main.html does not bring back the recommended products and throws this error on dataframe.

def content_based_recommendations(train_data, item_name, top_n=10):
    if item_name not in train_data['Name'].values:
        print(f"Item '{item_name}' not found in the training data.")
        return pd.DataFrame()

    tfidf_vectorizer = TfidfVectorizer(stop_words='english')
    tfidf_matrix_content = tfidf_vectorizer.fit_transform(train_data['Tags'])
    cosine_similarities_content = cosine_similarity(tfidf_matrix_content, tfidf_matrix_content)
    item_index = train_data[train_data['Name'] == item_name].index[0]
    similar_items = list(enumerate(cosine_similarities_content[item_index]))
    similar_items = sorted(similar_items, key=lambda x: x[1], reverse=True)
    top_similar_items = similar_items[1:top_n+1]
    recommended_item_indices = [x[0] for x in top_similar_items]
    recommended_items_details = train_data.iloc[recommended_item_indices][['Name', 'ReviewCount', 'Brand', 'ImageURL', 'Rating']]
    return recommended_items_details



@app.route("/recommendations", methods=['POST'])
def recommendations():
    try:
        prod = request.form.get('prod')
        nbr = request.form.get('nbr')

        if not prod or not nbr:
            return render_template('main.html', message="Product name or number of recommendations is missing.")

        try:
            nbr = int(nbr)
        except ValueError:
            return render_template('main.html', message="Invalid number of recommendations.")

        df = pd.read_csv('clean_data.csv')
        print(df.to_string())
        content_based_rec = content_based_recommendations(train_data, prod, top_n=nbr)

        if content_based_rec.empty:
            return render_template('main.html', message="No recommendations available for this product.")
        else:
            random_product_image_urls = [random.choice(random_image_urls) for _ in range(len(content_based_rec))]
            price = [40, 50, 60, 70, 100, 122, 106, 50, 30, 50]
            return render_template('main.html', content_based_rec=content_based_rec, truncate=truncate,
                                   random_product_image_urls=random_product_image_urls,
                                   random_price=random.choice(price))

    except Exception as e:
        return render_template('main.html', message=f"An error occurred: {str(e)}")

How to resolve it?

I was expecting the list of similar items displayed on the template.