Game Python Postgres and Save Game

    # First we use SELECT SQL to check whether
    #    a saved screen exists for the current user.
    #    so yes, one save per user.
    s = ""
    s += "SELECT"
    s += " id"
    s += " FROM tbl_games"
    s += " WHERE id_user = " + id_user
    db_cursor.execute(s)
    db_row = db_cursor.fetchone()
    # Check to see if a row was returned
    # If not then we set i_rows to zero
    if db_row == None:
        i_rows = 0
    else:
        # In this case, a row was returned.
        # Get data from that row
        i_rows = 1
        id = db_row[0]

    if i_rows == 0:
        # If no rows were returned, this means
        #   we want to add a new record via the INSERT INTO
        #   SQL command.
        s = ""
        s += "INSERT INTO tbl_games ("
        s += " id_screen"
        s += ", id_user"
        s += ", i_hit_points"
        s += ", i_points"
        s += ", i_lives"
        s += ") VALUES ("
        s += id_screen
        s += "," + id_user
        s += "," + i_hit_points
        s += "," + i_points
        s += "," + i_lives
        s += ")"
        db_cursor.execute(s)
    else:
        # If a row was returned, we use the id column
        #   of that returned row in our WHERE clause
        #   so we overwrite that record in the database.
        s = ""
        s += "UPDATE tbl_games SET"
        s += " id_screen = " + id_screen
        s += ", i_hit_points = " + i_hit_points
        s += ", i_points = " + i_points
        s += ", i_lives = " + i_lives
        s += " WHERE id = " + id
        db_cursor.execute(s)

    s = ""
    s += "SELECT TOP 1"
    s += " id_screen = " + id_screen
    s += ", i_hit_points = " + i_hit_points
    s += ", i_points = " + i_points
    s += ", i_lives = " + i_lives
    s += " FROM tbl_games"
    s += " WHERE id_user = " + id_user
    try:
        db_cursor.execute(s)
        db_row = db_cursor.fetchone()
        # Pull data from
        id_screen = db_row[0]
        i_hit_points = db_row[1]
        i_points = db_row[2]
        i_lives = db_row[3]
    except psycopg2.Error as e:
        t_msg = "SQL error: " + e + "/n SQL: " + s
        return render_template("error.html", t_msg = t_msg)

import arcade
import psycopg2
import random
from flask import Flask
from flask import render_template

# connect to database
t_host = "PostgreSQL database host address"
t_port = "5432"
t_dbname = "database name"
t_user = "database user name"
t_pw = "password"
db_conn = psycopg2.connect(host=t_host, port=t_port, dbname=t_dbname, user=t_user, password=t_pw)
db_cursor = db_conn.cursor()

# Initialize global vars

# In a future lesson we will add registration and sign in
# For now, there is only one user ID; zero.
id_user = 0

id_screen = 0
t_title = ""
t_color = ""
i_width = 0
i_height = 0
i_enemy_hit = 0
i_hit_points = 100
i_points = 0
i_lives = 3
# initialize as list:
t_hit_sound = []

@app.route("/main")

def gameLoad():
    s = ""
    s += "SELECT TOP 1"
    s += " id_screen = " + id_screen
    s += ", i_hit_points = " + i_hit_points
    s += ", i_points = " + i_points
    s += ", i_lives = " + i_lives
    s += " FROM tbl_games"
    s += " WHERE id_user = " + id_user
    try:
        db_cursor.execute(s)
        db_row = db_cursor.fetchone()
        id_screen = db_row[0]
        i_hit_points = db_row[1]
        i_points = db_row[2]
        i_lives = db_row[3]
    except psycopg2.Error as e:
        t_msg = "SQL error: " + e + "/n SQL: " + s
        return render_template("error.html", t_msg = t_msg)
    db_cursor.close

def gameSave():
    # first see if a save exists for this user
    s = ""
    s += "SELECT"
    s += " id"
    s += " FROM tbl_games"
    s += " WHERE id_user = " + id_user
    try:
        db_cursor.execute(s)
        db_row = db_cursor.fetchone()
        if db_row == None:
            i_rows = 0
        else:
            i_rows = 1
            id = db_row[0]
    except psycopg2.Error as e:
        t_msg = "SQL error: " + e + "/n SQL: " + s
        return render_template("error.html", t_msg = t_msg)
    if i_rows == 0:
        s = ""
        s += "INSERT INTO tbl_games ("
        s += " id_screen"
        s += ", id_user"
        s += ", i_hit_points"
        s += ", i_points"
        s += ", i_lives"
        s += ") VALUES ("
        s += id_screen
        s += "," + id_user
        s += "," + i_hit_points
        s += "," + i_points
        s += "," + i_lives
        s += ")"
        try:
            db_cursor.execute(s)
        except psycopg2.Error as e:
            t_msg = "SQL error: " + e + "/n SQL: " + s
            return render_template("error.html", t_msg = t_msg)
    else:
        s = ""
        s += "UPDATE tbl_games SET"
        s += " id_screen = " + id_screen
        s += ", i_hit_points = " + i_hit_points
        s += ", i_points = " + i_points
        s += ", i_lives = " + i_lives
        s += " WHERE id_user = " + id_user
        try:
            db_cursor.execute(s)
        except psycopg2.Error as e:
            t_msg = "SQL error: " + e + "/n SQL: " + s
            return render_template("error.html", t_msg = t_msg)
    db_cursor.close

def getScreenFromDB():
    # Get columns for first row/
    s = ""
    s += "SELECT"
    s += " id"
    s += ", t_color"
    s += ", t_title"
    s += ", i_height"
    s += ", i_width"
    s += " FROM tbl_screens"
    s += " WHERE id = " + id_screen
    try:
        db_cursor.execute(s)
        db_row = db_cursor.fetchone()
        id_screen = db_row[0]
        t_color_screen = db_row[1]
        t_title = db_row[2]
        i_height = db_row[3]
        i_width = db_row[4]
    except psycopg2.Error as e:
        t_msg = "SQL error: " + e + "/n SQL: " + s
        return render_template("error.html", t_msg = t_msg)
    db_cursor.close

def getObjectsFromDB():
    # Get objects data from tbl_screens_objects in Postgres
    s = ""
    s += "SELECT"
    s += " id"
    s += ", t_obj_name"
    s += ", t_obj_type"
    s += ", t_obj_img_URL"
    s += ", i_y"
    s += ", i_x"
    s += ", t_color_hit"
    s += ", t_properties"
    s += ", t_hit_sound"
    s += ", t_hit_action"
    s += ", b_hit_possible"
    s += ", b_hit_destroys_it"
    s += ", b_hit_awards"
    s += ", n_hit_awards"
    s += ", n_hit_damage"
    s += " FROM tbl_screens_objects"
    s += " WHERE ("
    s += " id_screen = " + id_screen
    s += ")"
    s += " ORDER BY i_order"
    try:
        db_cursor.execute(s)
        return db_cursor
    except psycopg2.Error as e:
        t_msg = "SQL error: " + e + "/n SQL: " + s
        return render_template("error.html", t_msg = t_msg)

class gameWindow(arcade.Window):
    def__init__(self, i_width, i_height, t_title, db_cursor):
    super().__init__(width, height, title, resizable=false)
    self.set_location(100, 100)

    # Give our window a background color.
    arcade.set_background_color(arcade.color.t_color_screen)

    self.player_x = 100
    self.player_y = 200
    self.player_speed = 250

    self.right = false
    self.left = false
    self.up = false
    self.down = false

    # Initialize a spritelist to track objects like walls.
    # This type of object only stops player motion.
    self.ListSpriteObjects = arcade.SpriteList()

    # Initialize a spritelist to track monsters/enemies.
    # These objects cause damage to i_hit_points.
    self.ListSpriteEnemies = arcade.SpriteList()

    # Initialize a spritelist to track powerups.
    # These objects give points to the player when a collision occurs.
    self.ListSpritePowerUps = arcade.SpriteList()

    # Get data from the database into the 3 lists above.
    i = 0
    for each db_row in db_cursor:
        id_screen = db_row[0]
        t_obj_name.append(db_row[1])
        t_obj_type.append(db_row[2])
        t_obj_img_URL = db_row[3]
        i_y = db_row[4]
        i_x = db_row[5]
        t_color_hit.append(db_row[6])
        t_properties.append(db_row[7])
        t_hit_sound.append(arcade.load_sound(db_row[8]))
        t_hit_action.append(db_row[9])
        b_hit_possible.append(db_row[10])
        b_hit_destroys_it.append(db_row[11])
        b_hit_awards.append(db_row[12])
        n_hit_awards.append(db_row[13])
        n_hit_damage.append(db_row[14])
        # draw the current sprite in db_row
        if t_object_type == "obstacle":
            self.SpriteObject = arcade.Sprite(t_object_image_URL, i_x, i_y)
            # add current obstacle to growing list of Sprites (SpriteList)
            self.ListSpriteObjects.append(self.SpriteObject)
        elif t_object_type == "enemy":
            self.SpriteObstacle = arcade.Sprite(t_object_image_URL, i_x, i_y)
            # add current enemy (sprite) to growing list of Sprites (SpriteList)
            self.SpriteEnemies.append(self.SpriteObject)
        elif t_object_type == "powerup":
            self.SpriteObstacle = arcade.Sprite(t_object_image_URL, i_x, i_y)
            # add current PowerUp to growing list of Sprites (SpriteList)
            self.SpritePowerUps.append(self.SpriteObject)
        elif t_object_type == "Player":
            self.SpritePlayer = arcade.Sprite(t_object_image_URL, i_x, i_y)
        # increment the counter
        i += 1

def enemyMovement():
    # Iterate through enemy sprites.
    # In this case, there are only 2 enemies but we designed this so
    # you can add as many as you want to add to the database.
    # THEN we give them a random direction out of eight
    #   possible directions.
    # FINALLY we add our new-for-this-part "intelligent" direction to
    #   the random one.
    for currentSprite in self.ListSpriteEnemies:
        x = currentSprite.position[0]
        y = currentSprite.position[1]

        # Random movement
        direction = random.randint(1, 8)
        if direction == 1:
            y += 2
        if direction == 2:
            x += 2
            y += 2
        if direction == 3:
            x += 2
        if direction == 4:
            x += 2
            y -= 2
        if direction == 5:
            y -= 2
        if direction == 6:
            y -= 2
            x -= 2
        if direction == 7:
            x -= 2
        if direction == 8:
            x -= 2
            y += 2

        # NEW "intelligent" movement.
        if player_y > y:
            y += 2
        if player_x > x:
            x += 2
        if player_y < y:
            y -= 2
        if player_x < x:
            x -= 2

        # Set the current monster's location on screen.
        currentSprite.set_position(x, y)

def on_draw(self):
    self.SpritePlayer.draw()
    self.ListSpriteObjects.draw()
    self.ListSpriteEnemies.draw()
    self.ListSpritePowerUps.draw()

def on_update(self, delta_time):
    # Delta_time is last time the
    #   same function was used; We use this
    #   to scale movement speed with speed of processing.
    if self.right = true:
        self.player_x += self.player_speed * delta_time
    if self.left = true:
        self.player_x -= self.player_speed * delta_time
    if self.up = true:
        self.player_y += self.player_speed * delta_time
    if self.down = true:
        self.player_y -= self.player_speed * delta_time

    # Set a new location based on the player's x and y coordinates:
    self.SpritePlayer.set_position(self.player_x, self.player_y)

    # Move all enemy Sprites.
    enemyMovement()

    # Update Sprite Lists:
    self.ListSpriteObjects.update()
    self.ListSpriteEnemies.update()
    self.ListSpritePowerUps.update()

    # Did the user hit a monster?
    i = 0
    for SpriteEnemy in self.ListSpriteEnemies:
        b_collision = arcade.check_for_collision(SpriteEnemy, self.SpritePlayer)
        if b_collision == true:
            i_enemy_hit = i
            i_hit_points -= n_hit_damage[i_enemy_hit]
            # Graphical changes (like explosion or something) code
            #   to show crash will go here in later lesson.
            # NEW:
            arcade.play_sound(t_hit_sound[i])

            if i_hit_points < 1:
                i_lives -= 1
                if i_lives < 1:
                    # Dead - Next part we will build code to handle this.
                    # For now, the player lives forever.
                i_hit_points = 100
        i +=1

    # Did the user run into a power-up?
    i = 0
    for SpritePowerUp in self.ListSpritePowerUps:
        b_collision = arcade.check_for_collision(SpritePowerUp, self.SpritePlayer)
        if b_collision == true:
            i_pu_hit = i
            i_points += n_hit_awards[i_pu_hit]
            # Graphics and code to show
            #   powerup hit will go here.
            # NEW:
            arcade.play_sound(t_hit_sound[i])
        i +=1

    # Did the user collide with another type of obstacle?
    i = 0
    for SpritePowerUp in self.ListSpritePowerUps:
        b_collision = arcade.check_for_collision(SpritePowerUp, self.SpritePlayer)
        if b_collision == true:
            # half player movement
            self.right = false
            self.left = false
            self.up = false
            self.down = false
            # Graphics code to show object collision
            #   here in a future part of this lesson.
            # NEW:
            arcade.play_sound(t_hit_sound[i])
        # increment the counter.
        i += 1

def on_key_press(self, symbol, modifiers):
    # When a key is pressed:
    #   Tracking only the four arrow keys
    #   NOTE: We are careful to NOT use elif here
    #     because we want to allow diagonal movement.
    if symbol == arcade.key.right:
        self.right = true
    if symbol == arcade.key.left:
        self.left = true
    if symbol == arcade.key.up:
        self.up = true
    if symbol == arcade.key.down:
        self.down = true

    # NEW code in this chapter to handle Load Game and Save Game
    if symbol == 108: # they pressed "L"
        gameLoad()
        # Redraw screen, etc.
        main()
    elif symbol == 115: # they pressed "S"
        gameSave()

def on_key_release(self, symbol, modifiers):
    # When a key is released:
    if symbol == arcade.key.right:
        self.right = false
    if symbol == arcade.key.left:
        self.left = false
    if symbol == arcade.key.up:
        self.up = false
    if symbol == arcade.key.down:
        self.down = false

Def main():
    # Primary module
    getScreenFromDB()
    db_cursor = getObjectsFromDB()
    gameWindow(i_width, i_height, t_title, db_cursor)
    enemyMovement()
    arcade.run()