Add type annotations

Author: lulunac27a

app.py

@@ -5,6 +5,7 @@
 import math
 from flask import Flask, render_template, redirect, url_for, request
 from flask_sqlalchemy import SQLAlchemy
+from werkzeug.wrappers import Response
 
 app = Flask(__name__)
 app.config["SQLALCHEMY_DATABASE_URI"] = "sqlite:///users.db"
@@ -16,17 +17,20 @@ class User(db.Model):  # user class
     A user model to store the level and experience points (XP).
     """
 
-    id = db.Column(db.Integer, primary_key=True,
-                   unique=True, nullable=False)  # user id
-    username = db.Column(db.String(80), unique=True,
-                         nullable=False)  # username
-    xp = db.Column(db.Float, default=0, nullable=False)  # user XP
-    xp_required = db.Column(db.Float, default=1,
-                            nullable=False)  # user XP required
-    total_xp = db.Column(db.Float, default=0, nullable=False)  # user total XP
-    level = db.Column(db.Integer, default=1, nullable=False)  # user level
-
-    def add_xp(self, amount):  # add XP
+    id: int = db.Column(
+        db.Integer, primary_key=True, unique=True, nullable=False
+    )  # user id
+    username: str = db.Column(
+        db.String(80), unique=True, nullable=False)  # username
+    xp: float = db.Column(db.Float, default=0, nullable=False)  # user XP
+    xp_required: float = db.Column(
+        db.Float, default=1, nullable=False
+    )  # user XP required
+    total_xp: float = db.Column(
+        db.Float, default=0, nullable=False)  # user total XP
+    level: int = db.Column(db.Integer, default=1, nullable=False)  # user level
+
+    def add_xp(self, amount: float) -> None:  # add XP
         """
         Add XP (experience points) to the user.
         amount - the amount to add XP.
@@ -35,7 +39,7 @@ def add_xp(self, amount):  # add XP
         self.total_xp += amount  # add total XP by amount
         self.check_level_up()  # check if user has leveled up
 
-    def check_level_up(self):  # check if user has leveled up
+    def check_level_up(self) -> None:  # check if user has leveled up
         """
         Check if the user has leveled up.
         """
@@ -52,27 +56,28 @@ def check_level_up(self):  # check if user has leveled up
             )  # increase XP required exponentially with slower growth at higher levels
             self.level += 1  # increase level
 
-    def get_xp_required(self):  # get required XP to next level
+    def get_xp_required(self) -> float:  # get required XP to next level
         """
         Get the required XP for the user to level up.
         """
         return self.xp_required
 
-    def get_level_progress(self):  # get level progress
+    def get_level_progress(self) -> float:  # get level progress
         """
         Get the level progress as a percentage.
         """
         return (self.xp / self.xp_required) * 100
 
 
 @app.template_filter("short_numeric")  # short numeric filter
-# get number in short numeric form with abbreviations
-def short_numeric_filter(value):
+def short_numeric_filter(
+    value: float,
+) -> str:  # get number in short numeric form with abbreviations
     """
     Get the abbreviated numeric value.
     value - the numeric value to convert.
     """
-    units = [
+    units: list[str] = [
         "",
         "K",
         "M",
@@ -97,7 +102,7 @@ def short_numeric_filter(value):
         "V",
     ]  # list of units with abbreviations
     exponent = 0
-    mantissa = value  # mantissa value from 1 to 999
+    mantissa: float = value  # mantissa value from 1 to 999
     while mantissa >= 1000:  # repeat until mantissa is within 1 to 999
         mantissa /= 1000
         exponent += 1
@@ -111,27 +116,27 @@ def short_numeric_filter(value):
 
 
 @app.route("/")  # index page
-def index():  # get index page template
+def index() -> str:  # get index page template
     """
     Return the index page containing a user.
     """
-    user = User.query.first()  # get first user
+    user: User | None = User.query.first()  # get first user
     # redirect to index page template
     return render_template("index.html", user=user)
 
 
 @app.route("/add_xp", methods=["POST"])  # add XP from POST method
-def add_xp():  # add XP
+def add_xp() -> Response:  # add XP
     """
     Add XP (experience points) based on entered amount.
     """
-    user = User.query.first()  # get first user
+    user: User | None = User.query.first()  # get first user
     user.add_xp(float(request.form["amount"]))  # parse amount as float
     db.session.commit()  # commit database changes
     return redirect(url_for("index"))  # redirect to index page template
 
 
-def init_db():  # initialize database
+def init_db() -> None:  # initialize database
     """
     Initialize the user database.
     """