add helper function GetGenreList - passes all genres to *.html, so horizontal "list" of checkboxes for book can be created

main.py

@@ -2,7 +2,7 @@ from flask import Flask, render_template, request
 from flask_sqlalchemy import SQLAlchemy
 from flask_marshmallow import Marshmallow
 from flask_bootstrap import Bootstrap
-from wtforms import SubmitField, StringField, HiddenField, SelectField, validators, Form
+from wtforms import SubmitField, StringField, HiddenField, SelectField, validators
 from flask_wtf import FlaskForm
 
 app = Flask(__name__)
@@ -17,7 +17,7 @@ Bootstrap(app)
 
 from author import Author, AuthorForm, AuthorSchema
 from publisher import Publisher, PublisherForm, PublisherSchema
-from genre import Genre, GenreForm, GenreSchema
+from genre import Genre, GenreForm, GenreSchema, GetGenreList
 from condition import Condition, ConditionForm, ConditionSchema
 from covertype import Covertype, CovertypeForm, CovertypeSchema
 from owned import Owned, OwnedForm, OwnedSchema
@@ -164,7 +164,8 @@ def book(id):
     book_form.owned.default = book.owned
     book_form.rating.default = book.rating
     book_form.process()
-    return render_template("book.html", books=book_s, subs=sub_book, book_form=book_form )
+    genre_list = GetGenreList()
+    return render_template("book.html", books=book_s, subs=sub_book, book_form=book_form, genre_list=genre_list )
 
 @app.route("/", methods=["GET"])
 def main_page():