diff --git a/primer-on-python-decorators/README.md b/primer-on-python-decorators/README.md
index 441cbffee1..3334f0aad8 100644
--- a/primer-on-python-decorators/README.md
+++ b/primer-on-python-decorators/README.md
@@ -1,17 +1,11 @@
 # Primer on Python Decorators
 
-Code examples from the [Primer on Python Decorators](https://realpython.com/primer-on-python-decorators/) tutorial on [Real Python](https://realpython.com/).
+Here you can find code examples from the [Primer on Python Decorators](https://realpython.com/primer-on-python-decorators/) tutorial on [Real Python](https://realpython.com/).
 
 ## Decorators
 
-As noted in the article, most decorators are stored in the file [`decorators.py`](https://github.com/realpython/materials/blob/master/primer-on-python-decorators/decorators.py). The exceptions are those decorators that depend on third party packages ([Flask](http://flask.pocoo.org/) and [Pint](https://pint.readthedocs.io/)), which are available in [`decorators_flask.py`](https://github.com/realpython/materials/blob/master/primer-on-python-decorators/decorators_flask.py) and [`decorators_unit.py`](https://github.com/realpython/materials/blob/master/primer-on-python-decorators/decorators_unit.py), respectively.
+You can find most decorators in the file `decorators.py`. The exceptions are those decorators that depend on the third-party packages ([Flask](http://flask.pocoo.org/) and [Pint](https://pint.readthedocs.io/)). These decorators are available in `secret_app.py`, `validate_input.py`, and `units.py`.
 
 ## Examples
 
-Most of the code examples from the article are available in the [`examples.py`](https://github.com/realpython/materials/blob/master/primer-on-python-decorators/examples.py) file.
-
-## Cheat Sheet
-
-We’ve put together a short & sweet Python decorators cheat sheet for you that summarizes the techniques explained in this tutorial:
-
-[Get the decorators cheat sheet »](https://realpython.com/optins/view/decorators-cheatsheet/)
+You can find many code examples from the tutorial in separate Python files.
diff --git a/primer-on-python-decorators/calculate_e.py b/primer-on-python-decorators/calculate_e.py
new file mode 100644
index 0000000000..4751b09fab
--- /dev/null
+++ b/primer-on-python-decorators/calculate_e.py
@@ -0,0 +1,13 @@
+import math
+
+from decorators import debug
+
+math.factorial = debug(math.factorial)
+
+
+def approximate_e(terms=18):
+    return sum(1 / math.factorial(n) for n in range(terms))
+
+
+if __name__ == "__main__":
+    print(approximate_e(5))
diff --git a/primer-on-python-decorators/circle.py b/primer-on-python-decorators/circle.py
new file mode 100644
index 0000000000..00a37626a8
--- /dev/null
+++ b/primer-on-python-decorators/circle.py
@@ -0,0 +1,35 @@
+class Circle:
+    def __init__(self, radius):
+        self.radius = radius
+
+    @property
+    def radius(self):
+        """Get value of radius"""
+        return self._radius
+
+    @radius.setter
+    def radius(self, value):
+        """Set radius, raise error if negative"""
+        if value >= 0:
+            self._radius = value
+        else:
+            raise ValueError("radius must be non-negative")
+
+    @property
+    def area(self):
+        """Calculate area inside circle"""
+        return self.pi() * self.radius**2
+
+    def cylinder_volume(self, height):
+        """Calculate volume of cylinder with circle as base"""
+        return self.area * height
+
+    @classmethod
+    def unit_circle(cls):
+        """Factory method creating a circle with radius 1"""
+        return cls(1)
+
+    @staticmethod
+    def pi():
+        """Value of π, could use math.pi instead though"""
+        return 3.1415926535
diff --git a/primer-on-python-decorators/class_decorators.py b/primer-on-python-decorators/class_decorators.py
new file mode 100644
index 0000000000..81e7464f55
--- /dev/null
+++ b/primer-on-python-decorators/class_decorators.py
@@ -0,0 +1,22 @@
+from decorators import debug, timer
+
+
+class TimeWaster:
+    @debug
+    def __init__(self, max_num):
+        self.max_num = max_num
+
+    @timer
+    def waste_time(self, num_times):
+        for _ in range(num_times):
+            sum([number**2 for number in range(self.max_num)])
+
+
+@timer
+class TimeWaster2:
+    def __init__(self, max_num):
+        self.max_num = max_num
+
+    def waste_time(self, num_times):
+        for _ in range(num_times):
+            sum([i**2 for i in range(self.max_num)])
diff --git a/primer-on-python-decorators/decorators.py b/primer-on-python-decorators/decorators.py
index bb9bbea352..b9e77d5ee3 100644
--- a/primer-on-python-decorators/decorators.py
+++ b/primer-on-python-decorators/decorators.py
@@ -1,21 +1,10 @@
-"""Examples of decorators
-
-See https://realpython.com/primer-on-python-decorators/
-
-The decorators with dependencies outside of the standard library (Flask
-and Pint) are available in separate files.
-"""
-
 import functools
 import time
 
-
-PLUGINS = dict()  # Dictionary used by @register to store plugins
+PLUGINS = dict()
 
 
 def do_twice(func):
-    """Run the decorated function twice"""
-
     @functools.wraps(func)
     def wrapper_do_twice(*args, **kwargs):
         func(*args, **kwargs)
@@ -33,7 +22,7 @@ def wrapper_timer(*args, **kwargs):
         value = func(*args, **kwargs)
         end_time = time.perf_counter()
         run_time = end_time - start_time
-        print(f"Finished {func.__name__!r} in {run_time:.4f} secs")
+        print(f"Finished {func.__name__}() in {run_time:.4f} secs")
         return value
 
     return wrapper_timer
@@ -45,25 +34,25 @@ def debug(func):
     @functools.wraps(func)
     def wrapper_debug(*args, **kwargs):
         args_repr = [repr(a) for a in args]
-        kwargs_repr = [f"{k}={v!r}" for k, v in kwargs.items()]
+        kwargs_repr = [f"{k}={repr(v)}" for k, v in kwargs.items()]
         signature = ", ".join(args_repr + kwargs_repr)
         print(f"Calling {func.__name__}({signature})")
         value = func(*args, **kwargs)
-        print(f"{func.__name__!r} returned {value!r}")
+        print(f"{func.__name__}() returned {repr(value)}")
         return value
 
     return wrapper_debug
 
 
-def slow_down_1sec(func):
+def slow_down_one_second(func):
     """Sleep 1 second before calling the function"""
 
     @functools.wraps(func)
-    def wrapper_slow_down(*args, **kwargs):
+    def wrapper_slow_down_one_second(*args, **kwargs):
         time.sleep(1)
         return func(*args, **kwargs)
 
-    return wrapper_slow_down
+    return wrapper_slow_down_one_second
 
 
 def register(func):
@@ -73,8 +62,6 @@ def register(func):
 
 
 def repeat(_func=None, *, num_times=2):
-    """Run the decorated function the given number of times"""
-
     def decorator_repeat(func):
         @functools.wraps(func)
         def wrapper_repeat(*args, **kwargs):
@@ -91,12 +78,10 @@ def wrapper_repeat(*args, **kwargs):
 
 
 def count_calls(func):
-    """Count the number of calls made to the decorated function"""
-
     @functools.wraps(func)
     def wrapper_count_calls(*args, **kwargs):
         wrapper_count_calls.num_calls += 1
-        print(f"Call {wrapper_count_calls.num_calls} of {func.__name__!r}")
+        print(f"Call {wrapper_count_calls.num_calls} of {func.__name__}()")
         return func(*args, **kwargs)
 
     wrapper_count_calls.num_calls = 0
@@ -104,8 +89,6 @@ def wrapper_count_calls(*args, **kwargs):
 
 
 class CountCalls:
-    """Count the number of calls made to the decorated function"""
-
     def __init__(self, func):
         functools.update_wrapper(self, func)
         self.func = func
@@ -113,7 +96,7 @@ def __init__(self, func):
 
     def __call__(self, *args, **kwargs):
         self.num_calls += 1
-        print(f"Call {self.num_calls} of {self.func.__name__!r}")
+        print(f"Call {self.num_calls} of {self.func.__name__}()")
         return self.func(*args, **kwargs)
 
 
@@ -139,7 +122,7 @@ def singleton(cls):
 
     @functools.wraps(cls)
     def wrapper_singleton(*args, **kwargs):
-        if not wrapper_singleton.instance:
+        if wrapper_singleton.instance is None:
             wrapper_singleton.instance = cls(*args, **kwargs)
         return wrapper_singleton.instance
 
@@ -157,15 +140,5 @@ def wrapper_cache(*args, **kwargs):
             wrapper_cache.cache[cache_key] = func(*args, **kwargs)
         return wrapper_cache.cache[cache_key]
 
-    wrapper_cache.cache = dict()
+    wrapper_cache.cache = {}
     return wrapper_cache
-
-
-def set_unit(unit):
-    """Register a unit on a function"""
-
-    def decorator_set_unit(func):
-        func.unit = unit
-        return func
-
-    return decorator_set_unit
diff --git a/primer-on-python-decorators/decorators_flask.py b/primer-on-python-decorators/decorators_flask.py
deleted file mode 100644
index e96f8c9533..0000000000
--- a/primer-on-python-decorators/decorators_flask.py
+++ /dev/null
@@ -1,42 +0,0 @@
-"""Examples of decorators that work with Flask
-
-See  https://realpython.com/primer-on-python-decorators/
-
-These decorators depend on the third party package Flask:
-
-    http://flask.pocoo.org/
-"""
-
-import functools
-
-# pip install Flask
-from flask import abort, g, request, redirect, url_for
-
-
-def login_required(func):
-    """Make sure user is logged in before proceeding"""
-
-    @functools.wraps(func)
-    def wrapper_login_required(*args, **kwargs):
-        if g.user is None:
-            return redirect(url_for("login", next=request.url))
-        return func(*args, **kwargs)
-
-    return wrapper_login_required
-
-
-def validate_json(*expected_args):
-    """Validate that a json-request contains the expected parameters"""
-
-    def decorator_validate_json(func):
-        @functools.wraps(func)
-        def wrapper_validate_json(*args, **kwargs):
-            json_object = request.get_json()
-            for expected_arg in expected_args:
-                if expected_arg not in json_object:
-                    abort(400)
-            return func(*args, **kwargs)
-
-        return wrapper_validate_json
-
-    return decorator_validate_json
diff --git a/primer-on-python-decorators/examples.py b/primer-on-python-decorators/examples.py
deleted file mode 100644
index 0cdeedec2e..0000000000
--- a/primer-on-python-decorators/examples.py
+++ /dev/null
@@ -1,243 +0,0 @@
-"""Examples using decorators
-
-See https://realpython.com/primer-on-python-decorators/
-
-This file contains code for many of the examples in the text. You can
-find the decorators themselves in the decorators.py file.
-"""
-
-from datetime import datetime
-import functools
-import math
-import random
-
-from decorators import (
-    cache,
-    count_calls,
-    debug,
-    do_twice,
-    PLUGINS,
-    register,
-    set_unit,
-    singleton,
-    slow_down,
-    timer,
-)
-
-
-# First-Class Objects
-def say_hello(name):
-    return f"Hello {name}"
-
-
-def be_awesome(name):
-    return f"Yo {name}, together we are the awesomest!"
-
-
-def greet_bob(greeter_func):
-    return greeter_func("Bob")
-
-
-# Returning Functions From Functions
-def parent(num):
-    def first_child():
-        return "Hi, I am Emma"
-
-    def second_child():
-        return "Call me Liam"
-
-    if num == 1:
-        return first_child
-    else:
-        return second_child
-
-
-# Simple Decorators
-def not_during_the_night(func):
-    def wrapper():
-        if 7 <= datetime.now().hour < 22:
-            func()
-        else:
-            pass  # Hush, the neighbors are asleep.
-
-    return wrapper
-
-
-# Syntactic Sugar!
-def my_decorator(func):
-    def wrapper():
-        print("Something is happening before the function is called.")
-        func()
-        print("Something is happening after the function is called.")
-
-    return wrapper
-
-
-@my_decorator
-def say_whee():
-    print("Whee!")
-
-
-# Reusing Decorators
-@do_twice
-def say_whee_twice():
-    print("Whee!")
-
-
-# Returning Values From Decorated Functions
-@do_twice
-def return_greeting(name):
-    print("Creating greeting")
-    return f"Hi {name}"
-
-
-# A Few Real World Examples
-def decorator(func):
-    @functools.wraps(func)
-    def wrapper_decorator(*args, **kwargs):
-        # Do something before.
-        value = func(*args, **kwargs)
-        # Do something after.
-        return value
-
-    return wrapper_decorator
-
-
-# Timing Functions
-@timer
-def waste_some_time(num_times):
-    for _ in range(num_times):
-        sum([i**2 for i in range(10000)])
-
-
-# Debugging Code
-@debug
-def make_greeting(name, age=None):
-    if age is None:
-        return f"Howdy {name}!"
-    else:
-        return f"Whoa {name}! {age} already, you are growing up!"
-
-
-# Apply a decorator to a standard library function
-math.factorial = debug(math.factorial)
-
-
-def approximate_e(terms=18):
-    return sum(1 / math.factorial(n) for n in range(terms))
-
-
-# Slowing Down Code (Revisited)
-@slow_down
-def countdown(from_number):
-    if from_number < 1:
-        print("Liftoff!")
-    else:
-        print(from_number)
-        countdown(from_number - 1)
-
-
-# Registering Plugins
-#
-# The names of the plugins have been changed from the text to avoid name
-# clashes with earlier examples
-@register
-def say_hi(name):
-    return f"Hi {name}"
-
-
-@register
-def be_cool(name):
-    return f"Yo {name}, together we are the coolest!"
-
-
-def randomly_greet(name):
-    greeter, greeter_func = random.choice(list(PLUGINS.items()))
-    print(f"Using {greeter!r}")
-    return greeter_func(name)
-
-
-# Example Using Built-in Class Decorators
-class Circle:
-    def __init__(self, radius):
-        self._radius = radius
-
-    @property
-    def radius(self):
-        """Get value of radius"""
-        return self._radius
-
-    @radius.setter
-    def radius(self, value):
-        """Set radius, raise error if negative"""
-        if value >= 0:
-            self._radius = value
-        else:
-            raise ValueError("Radius must be positive")
-
-    @property
-    def area(self):
-        """Calculate area inside circle"""
-        return self.pi() * self.radius**2
-
-    def cylinder_volume(self, height):
-        """Calculate volume of cylinder with circle as base"""
-        return self.area * height
-
-    @classmethod
-    def unit_circle(cls):
-        """Factory method creating a circle with radius 1"""
-        return cls(1)
-
-    @staticmethod
-    def pi():
-        """Value of π, could use math.pi instead though"""
-        return 3.141_592_653_5
-
-
-# Decorating Classes
-class TimeWaster:
-    @debug
-    def __init__(self, max_num):
-        self.max_num = max_num
-
-    @timer
-    def waste_time(self, num_times):
-        for _ in range(num_times):
-            sum([i**2 for i in range(self.max_num)])
-
-
-# Nesting Decorators
-@do_twice
-@debug
-def greet(name):
-    print(f"Hello {name}")
-
-
-# Creating Singletons
-@singleton
-class TheOne:
-    pass
-
-
-# Caching Return Values
-@cache
-@count_calls
-def fibonacci(num):
-    if num < 2:
-        return num
-    return fibonacci(num - 1) + fibonacci(num - 2)
-
-
-@functools.lru_cache(maxsize=4)  # lru_cache is preferred to rolling your own
-def fibonacci_lru(num):
-    print(f"Calculating fibonacci({num})")
-    if num < 2:
-        return num
-    return fibonacci(num - 1) + fibonacci(num - 2)
-
-
-# Adding Information About Units
-@set_unit("cm^3")
-def volume(radius, height):
-    return math.pi * radius**2 * height
diff --git a/primer-on-python-decorators/greeters.py b/primer-on-python-decorators/greeters.py
new file mode 100644
index 0000000000..d703402a1d
--- /dev/null
+++ b/primer-on-python-decorators/greeters.py
@@ -0,0 +1,15 @@
+def say_hello(name):
+    return f"Hello {name}"
+
+
+def be_awesome(name):
+    return f"Yo {name}, together we're the awesomest!"
+
+
+def greet_bob(greeter_func):
+    return greeter_func("Bob")
+
+
+if __name__ == "__main__":
+    print(greet_bob(say_hello))
+    print(greet_bob(be_awesome))
diff --git a/primer-on-python-decorators/hello_decorator.py b/primer-on-python-decorators/hello_decorator.py
new file mode 100644
index 0000000000..ba174359f7
--- /dev/null
+++ b/primer-on-python-decorators/hello_decorator.py
@@ -0,0 +1,24 @@
+def decorator(func):
+    def wrapper():
+        print("Something is happening before the function is called.")
+        func()
+        print("Something is happening after the function is called.")
+
+    return wrapper
+
+
+def say_whee():
+    print("Whee!")
+
+
+say_whee = decorator(say_whee)
+
+
+@decorator
+def say_whee2():
+    print("Whee!")
+
+
+if __name__ == "__main__":
+    say_whee()
+    say_whee2()
diff --git a/primer-on-python-decorators/inner_functions.py b/primer-on-python-decorators/inner_functions.py
new file mode 100644
index 0000000000..6ed904781e
--- /dev/null
+++ b/primer-on-python-decorators/inner_functions.py
@@ -0,0 +1,33 @@
+def parent():
+    print("Printing from parent()")
+
+    def first_child():
+        print("Printing from first_child()")
+
+    def second_child():
+        print("Printing from second_child()")
+
+    second_child()
+    first_child()
+
+
+def get_child(num):
+    def first_child():
+        return "Hi, I'm Elias"
+
+    def second_child():
+        return "Call me Ester"
+
+    if num == 1:
+        return first_child
+    else:
+        return second_child
+
+
+if __name__ == "__main__":
+    parent()
+
+    first = get_child(1)
+    second = get_child(2)
+    print(first())
+    print(second())
diff --git a/primer-on-python-decorators/quiet_night.py b/primer-on-python-decorators/quiet_night.py
new file mode 100644
index 0000000000..ff9ce6141d
--- /dev/null
+++ b/primer-on-python-decorators/quiet_night.py
@@ -0,0 +1,21 @@
+from datetime import datetime
+
+
+def not_during_the_night(func):
+    def wrapper():
+        if 7 <= datetime.now().hour < 22:
+            func()
+        else:
+            pass  # Hush, the neighbors are asleep
+
+    return wrapper
+
+
+def say_whee():
+    print("Whee!")
+
+
+say_whee = not_during_the_night(say_whee)
+
+if __name__ == "__main__":
+    say_whee()
diff --git a/primer-on-python-decorators/secret_app.py b/primer-on-python-decorators/secret_app.py
new file mode 100644
index 0000000000..02c6557c44
--- /dev/null
+++ b/primer-on-python-decorators/secret_app.py
@@ -0,0 +1,22 @@
+import functools
+from flask import Flask, g, request, redirect, url_for
+
+app = Flask(__name__)
+
+
+def login_required(func):
+    """Make sure user is logged in before proceeding"""
+
+    @functools.wraps(func)
+    def wrapper_login_required(*args, **kwargs):
+        if g.user is None:
+            return redirect(url_for("login", next=request.url))
+        return func(*args, **kwargs)
+
+    return wrapper_login_required
+
+
+@app.route("/secret")
+@login_required
+def secret():
+    ...
diff --git a/primer-on-python-decorators/decorators_unit.py b/primer-on-python-decorators/units.py
similarity index 71%
rename from primer-on-python-decorators/decorators_unit.py
rename to primer-on-python-decorators/units.py
index cb116f177c..1295477894 100644
--- a/primer-on-python-decorators/decorators_unit.py
+++ b/primer-on-python-decorators/units.py
@@ -1,15 +1,6 @@
-"""Examples of decorators dealing with units
-
-See https://realpython.com/primer-on-python-decorators/
-
-These decorators depend on the third party package Pint:
-
-    http://pint.readthedocs.io/
-"""
-
 import functools
 
-import pint  # pip install Pint
+import pint
 
 
 def set_unit(unit):
diff --git a/primer-on-python-decorators/validate_input.py b/primer-on-python-decorators/validate_input.py
new file mode 100644
index 0000000000..adf662675f
--- /dev/null
+++ b/primer-on-python-decorators/validate_input.py
@@ -0,0 +1,28 @@
+import functools
+
+from flask import Flask, abort, request
+
+app = Flask(__name__)
+
+
+def validate_json(*expected_args):
+    def decorator_validate_json(func):
+        @functools.wraps(func)
+        def wrapper_validate_json(*args, **kwargs):
+            json_object = request.get_json()
+            for expected_arg in expected_args:
+                if expected_arg not in json_object:
+                    abort(400)
+            return func(*args, **kwargs)
+
+        return wrapper_validate_json
+
+    return decorator_validate_json
+
+
+@app.route("/grade", methods=["POST"])
+@validate_json("student_id")
+def update_grade():
+    json_data = request.get_json()  # noqa
+    # Update database.
+    return "success!"