TypeError: unsupported operand type(s) for +: 'int' and 'RowProxy'

The purpose of this view is to extract and return into JSON format after reading from goodread.com and my database by some calculation.

I tried so many ways to render the API but still no hope

I tried changing user input oneIsbn with 'oneIsbn' while querying in each listed SQL queries. what I got on my browser is just like this

{ "Error": "Invalid ISBN 0380795272" }

My code snippet

@app.route("/api/<oneIsbn>", methods=["GET", "POST"])
@login_required
def api(oneIsbn):
    """Returns in JSON format for a single Book"""

    if request.method == "GET":

        check = db.execute("SELECT * FROM books WHERE isbn= :isbn",
                           {"isbn": oneIsbn}).fetchone()
        if check is None:
               return jsonify({"Error": f"Invalid ISBN {oneIsbn}"}), 405
        else:
            res = requests.get(
                "https://www.goodreads.com/book/review_counts.json",
                params={
                    "key": "x9fJg",
                    "isbns": oneIsbn})
            if res.status_code != 200:
                raise Exception("ERROR: API request unsuccessful.")
            else:
                data = res.json()
                y = data["books"][0]["work_reviews_count"]
                r = data["books"][0]["average_rating"]

            isbn = db.execute("SELECT isbn FROM books WHERE isbn = :isbn",
                                {"isbn": oneIsbn}).fetchone()
            title = db.execute("SELECT title FROM books WHERE isbn = :isbn",
                                {"isbn": oneIsbn}).fetchone()
            author = db.execute("SELECT author FROM books WHERE isbn = :isbn",
                                {"isbn": oneIsbn}).fetchone()
            year = db.execute("SELECT year FROM books WHERE isbn = :isbn",
                                {"isbn": oneIsbn}).fetchone()
            x = db.execute("SELECT COUNT(reviews) FROM reviews WHERE isbn = :isbn",
                                    {"isbn": 'oneIsbn'}).fetchone()
            z = db.execute("SELECT rating FROM reviews WHERE isbn = :isbn",
                                    {"isbn": oneIsbn}).fetchone()

            rev = int(y)
            revCount = int(x.count)
            bothReviewValue = sum((revCount,rev))

            # listRate = float(z)
            rat = float(r)
            bothRatingValue = sum([z,rat]) / 2

            return jsonify(
                ISBN=isbn,
                TITLE=title,
                AUTHOR=author,
                YEAR=year,
                REVIEWS=bothReviewValue,
                RATING=bothRatingValue
                ), 422 

TRACEBACK

TypeError
TypeError: unsupported operand type(s) for +: 'int' and 'RowProxy'

Traceback (most recent call last)
File "C:\Users\Beacon\AppData\Local\Programs\Python\Python38\Lib\site-packages\flask\app.py", line 2464, in __call__
return self.wsgi_app(environ, start_response)
File "C:\Users\Beacon\AppData\Local\Programs\Python\Python38\Lib\site-packages\flask\app.py", line 2450, in wsgi_app
response = self.handle_exception(e)
File "C:\Users\Beacon\AppData\Local\Programs\Python\Python38\Lib\site-packages\flask\app.py", line 1867, in handle_exception
reraise(exc_type, exc_value, tb)
File "C:\Users\Beacon\AppData\Local\Programs\Python\Python38\Lib\site-packages\flask\_compat.py", line 39, in reraise
raise value
File "C:\Users\Beacon\AppData\Local\Programs\Python\Python38\Lib\site-packages\flask\app.py", line 2447, in wsgi_app
response = self.full_dispatch_request()
File "C:\Users\Beacon\AppData\Local\Programs\Python\Python38\Lib\site-packages\flask\app.py", line 1952, in full_dispatch_request
rv = self.handle_user_exception(e)
File "C:\Users\Beacon\AppData\Local\Programs\Python\Python38\Lib\site-packages\flask\app.py", line 1821, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "C:\Users\Beacon\AppData\Local\Programs\Python\Python38\Lib\site-packages\flask\_compat.py", line 39, in reraise
Open an interactive python shell in this frameraise value
File "C:\Users\Beacon\AppData\Local\Programs\Python\Python38\Lib\site-packages\flask\app.py", line 1950, in full_dispatch_request
rv = self.dispatch_request()
File "C:\Users\Beacon\AppData\Local\Programs\Python\Python38\Lib\site-packages\flask\app.py", line 1936, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "C:\Users\Beacon\Desktop\THINKFUL DOCS\PYTHON\PYTHON WORKSPACE\project1\application.py", line 39, in wrapped_view
return view(**kwargs)
File "C:\Users\Beacon\Desktop\THINKFUL DOCS\PYTHON\PYTHON WORKSPACE\project1\application.py", line 233, in api
bothRatingValue = sum([z,rat]) / 2
TypeError: unsupported operand type(s) for +: 'int' and 'RowProxy'
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This method I used really works great. I already missed something like

The sum method should be put in tuple not in list and the pulled string rate should cast to float.

            rev = int(y)
            revCount = int(x.count)
            bothReviewValue = sum((revCount,rev))

            listRate = float(z)
            rat = float(r)
            bothRatingValue = sum((listRate,rat)) / 2