From 880dfe852dd2cabaee4faf3552b00e2d4a2f4b34 Mon Sep 17 00:00:00 2001
From: Leodanis Pozo Ramos <lpozor78@gmail.com>
Date: Mon, 3 Jun 2024 20:10:04 +0200
Subject: [PATCH 1/3] Sample code for the article on built-in functions

---
 python-built-in-functions/README.md       |  3 ++
 python-built-in-functions/birds.py        | 11 ++++++
 python-built-in-functions/calculations.py | 16 ++++++++
 python-built-in-functions/circle.py       | 20 ++++++++++
 python-built-in-functions/commands.py     | 28 ++++++++++++++
 python-built-in-functions/config.json     |  5 +++
 python-built-in-functions/config.py       | 12 ++++++
 python-built-in-functions/evaluator.py    |  7 ++++
 python-built-in-functions/factory.py      | 21 +++++++++++
 python-built-in-functions/fibonacci.py    | 12 ++++++
 python-built-in-functions/files.py        |  2 +
 python-built-in-functions/formatting.py   |  8 ++++
 python-built-in-functions/guess.py        | 18 +++++++++
 python-built-in-functions/invert.py       | 20 ++++++++++
 python-built-in-functions/mean.py         |  5 +++
 python-built-in-functions/menu.py         |  9 +++++
 python-built-in-functions/person.py       |  9 +++++
 python-built-in-functions/point.py        | 14 +++++++
 python-built-in-functions/point_v1.py     | 27 ++++++++++++++
 python-built-in-functions/point_v2.py     | 25 +++++++++++++
 python-built-in-functions/powers.py       | 13 +++++++
 python-built-in-functions/processors.py   | 45 +++++++++++++++++++++++
 python-built-in-functions/products.csv    |  6 +++
 python-built-in-functions/progress.py     | 16 ++++++++
 python-built-in-functions/reader.py       |  7 ++++
 python-built-in-functions/shapes.py       | 15 ++++++++
 python-built-in-functions/stack.py        | 12 ++++++
 python-built-in-functions/uppercase.py    |  9 +++++
 28 files changed, 395 insertions(+)
 create mode 100644 python-built-in-functions/README.md
 create mode 100644 python-built-in-functions/birds.py
 create mode 100644 python-built-in-functions/calculations.py
 create mode 100644 python-built-in-functions/circle.py
 create mode 100644 python-built-in-functions/commands.py
 create mode 100644 python-built-in-functions/config.json
 create mode 100644 python-built-in-functions/config.py
 create mode 100644 python-built-in-functions/evaluator.py
 create mode 100644 python-built-in-functions/factory.py
 create mode 100644 python-built-in-functions/fibonacci.py
 create mode 100644 python-built-in-functions/files.py
 create mode 100644 python-built-in-functions/formatting.py
 create mode 100644 python-built-in-functions/guess.py
 create mode 100644 python-built-in-functions/invert.py
 create mode 100644 python-built-in-functions/mean.py
 create mode 100644 python-built-in-functions/menu.py
 create mode 100644 python-built-in-functions/person.py
 create mode 100644 python-built-in-functions/point.py
 create mode 100644 python-built-in-functions/point_v1.py
 create mode 100644 python-built-in-functions/point_v2.py
 create mode 100644 python-built-in-functions/powers.py
 create mode 100644 python-built-in-functions/processors.py
 create mode 100644 python-built-in-functions/products.csv
 create mode 100644 python-built-in-functions/progress.py
 create mode 100644 python-built-in-functions/reader.py
 create mode 100644 python-built-in-functions/shapes.py
 create mode 100644 python-built-in-functions/stack.py
 create mode 100644 python-built-in-functions/uppercase.py

diff --git a/python-built-in-functions/README.md b/python-built-in-functions/README.md
new file mode 100644
index 0000000000..6bf952a0df
--- /dev/null
+++ b/python-built-in-functions/README.md
@@ -0,0 +1,3 @@
+# Python's Built-in Functions: A Complete Exploration
+
+This folder provides the code examples for the Real Python tutorial [Python's Built-in Functions: A Complete Exploration](https://realpython.com/python-built-in-functions/).
diff --git a/python-built-in-functions/birds.py b/python-built-in-functions/birds.py
new file mode 100644
index 0000000000..40d87865df
--- /dev/null
+++ b/python-built-in-functions/birds.py
@@ -0,0 +1,11 @@
+class Duck:
+    def fly(self):
+        print("The duck is flying")
+
+    def swim(self):
+        print("The duck is swimming")
+
+
+class Pigeon:
+    def fly(self):
+        print("The pigeon is flying")
diff --git a/python-built-in-functions/calculations.py b/python-built-in-functions/calculations.py
new file mode 100644
index 0000000000..a2a2e46e5f
--- /dev/null
+++ b/python-built-in-functions/calculations.py
@@ -0,0 +1,16 @@
+functions = [
+    "def add(a, b): return a + b",
+    "def subtract(a, b): return a - b",
+    "def multiply(a, b): return a * b",
+    "def divide(a, b): return a / b",
+]
+
+
+for function in functions:
+    exec(function)
+
+
+add(1, 2)
+subtract(3, 2)
+multiply(2, 3)
+divide(6, 3)
diff --git a/python-built-in-functions/circle.py b/python-built-in-functions/circle.py
new file mode 100644
index 0000000000..ced4dabcdf
--- /dev/null
+++ b/python-built-in-functions/circle.py
@@ -0,0 +1,20 @@
+from time import sleep
+
+SENTINEL = object()
+
+
+class Circle:
+    def __init__(self, radius):
+        self.radius = radius
+        self._diameter = SENTINEL
+
+    @property
+    def diameter(self):
+        if self._diameter is SENTINEL:
+            sleep(0.5)  # Simulate a costly computation
+            self._diameter = self.radius * 2
+        return self._diameter
+
+
+circle = Circle(5)
+print(circle.diameter)
diff --git a/python-built-in-functions/commands.py b/python-built-in-functions/commands.py
new file mode 100644
index 0000000000..48f171fc6b
--- /dev/null
+++ b/python-built-in-functions/commands.py
@@ -0,0 +1,28 @@
+class CommandProcessor:
+    def __init__(self):
+        self.commands = {}
+
+    def register_command(self, command):
+        if not callable(command):
+            raise ValueError("command is not callable")
+        self.commands[command.__name__] = command
+
+    def execute_command(self, name, *args, **kwargs):
+        if (command := self.commands.get(name)) is None:
+            raise ValueError(f"command '{name}' not found")
+        return command(*args, **kwargs)
+
+
+def add(a, b):
+    return a + b
+
+
+subtract = 3 - 2
+
+
+command_processor = CommandProcessor()
+command_processor.register_command(add)
+command_processor.register_command(subtract)
+
+print(command_processor.execute_command("add", 1, 2))
+print(command_processor.register_command(subtract))
diff --git a/python-built-in-functions/config.json b/python-built-in-functions/config.json
new file mode 100644
index 0000000000..a30d2f4107
--- /dev/null
+++ b/python-built-in-functions/config.json
@@ -0,0 +1,5 @@
+{
+    "DATABASE_URL": "postgres://user:pass@localhost/dbname",
+    "DEBUG_MODE": true,
+    "MAX_CONNECTIONS": 10
+}
\ No newline at end of file
diff --git a/python-built-in-functions/config.py b/python-built-in-functions/config.py
new file mode 100644
index 0000000000..28ae455a4b
--- /dev/null
+++ b/python-built-in-functions/config.py
@@ -0,0 +1,12 @@
+import json
+
+
+def load_config(config_file):
+    with open(config_file) as file:
+        config = json.load(file)
+
+    globals().update(config)
+
+
+load_config("config.json")
+print(globals())
diff --git a/python-built-in-functions/evaluator.py b/python-built-in-functions/evaluator.py
new file mode 100644
index 0000000000..6cc2eeb800
--- /dev/null
+++ b/python-built-in-functions/evaluator.py
@@ -0,0 +1,7 @@
+def evaluator(expression):
+    numbers = [2, 3, 4, 5]
+    n = len(numbers)
+    return eval(expression, {}, {"numbers": numbers, "n": n})
+
+
+print(evaluator("sum(numbers) / n + 100"))  # 3.5
diff --git a/python-built-in-functions/factory.py b/python-built-in-functions/factory.py
new file mode 100644
index 0000000000..a19647339b
--- /dev/null
+++ b/python-built-in-functions/factory.py
@@ -0,0 +1,21 @@
+def create_class(name, custom_members):
+    def __init__(self, **kwargs):
+        self.__dict__.update(kwargs)
+
+    def __repr__(self):
+        return f"{name}({self.__dict__})"
+
+    class_members = {
+        "__init__": __init__,
+        "__repr__": __repr__,
+    }
+    class_members.update(custom_members)
+
+    return type(name, (), class_members)
+
+
+User = create_class("User", {"name": "", "age": 0, "email": ""})
+Product = create_class("Product", {"name": "", "price": 0.0, "units": 0})
+
+john = User(name="John", age=30, email="john@example.com")
+table = Product(name="Table", price=200.0, units=5)
diff --git a/python-built-in-functions/fibonacci.py b/python-built-in-functions/fibonacci.py
new file mode 100644
index 0000000000..c4f674db02
--- /dev/null
+++ b/python-built-in-functions/fibonacci.py
@@ -0,0 +1,12 @@
+class Fibonacci:
+    def __init__(self):
+        self._cache = [0, 1]
+
+    def __call__(self, index):
+        if index < len(self._cache):
+            fib_number = self._cache[index]
+            print(f"{fib_number} id = {id(fib_number)}")
+        else:
+            fib_number = self(index - 1) + self(index - 2)
+            self._cache.append(fib_number)
+        return fib_number
diff --git a/python-built-in-functions/files.py b/python-built-in-functions/files.py
new file mode 100644
index 0000000000..2a2e0a5c8c
--- /dev/null
+++ b/python-built-in-functions/files.py
@@ -0,0 +1,2 @@
+with open("fruits.txt") as file:
+    print(file.read())
diff --git a/python-built-in-functions/formatting.py b/python-built-in-functions/formatting.py
new file mode 100644
index 0000000000..8be856253d
--- /dev/null
+++ b/python-built-in-functions/formatting.py
@@ -0,0 +1,8 @@
+class Formatter:
+    @staticmethod
+    def as_currency(value):
+        return f"${value:,.2f}"
+
+    @staticmethod
+    def as_percent(value):
+        return f"{value:.2%}"
diff --git a/python-built-in-functions/guess.py b/python-built-in-functions/guess.py
new file mode 100644
index 0000000000..6d0cac893e
--- /dev/null
+++ b/python-built-in-functions/guess.py
@@ -0,0 +1,18 @@
+from random import randint
+
+LOW, HIGH = 1, 10
+
+secret_number = randint(LOW, HIGH)
+clue = ""
+
+while True:
+    guess = input(f"Guess a number between {LOW} and {HIGH} {clue} ")
+    number = int(guess)
+    if number > secret_number:
+        clue = f"(less than {number})"
+    elif number < secret_number:
+        clue = f"(greater than {number})"
+    else:
+        break
+
+print(f"You guessed it! The secret number is {number}")
diff --git a/python-built-in-functions/invert.py b/python-built-in-functions/invert.py
new file mode 100644
index 0000000000..9320b2c726
--- /dev/null
+++ b/python-built-in-functions/invert.py
@@ -0,0 +1,20 @@
+def invert_case(text):
+    result = ""
+    shift = ord("a") - ord("A")
+
+    for char in text:
+        code_point = ord(char)
+        if char.islower():
+            result += chr(code_point - shift)
+        elif char.isupper():
+            result += chr(code_point + shift)
+        else:
+            result += char
+
+    return result
+
+
+# Example usage
+example_string = "Hello, World!"
+print("Original:", example_string)
+print("Inverted Case:", invert_case(example_string))
diff --git a/python-built-in-functions/mean.py b/python-built-in-functions/mean.py
new file mode 100644
index 0000000000..f201a5d272
--- /dev/null
+++ b/python-built-in-functions/mean.py
@@ -0,0 +1,5 @@
+def mean(values):
+    try:
+        return sum(values) / len(values)
+    except ZeroDivisionError:
+        raise ValueError("mean() arg shouldn't be empty") from None
diff --git a/python-built-in-functions/menu.py b/python-built-in-functions/menu.py
new file mode 100644
index 0000000000..7e7ff78f7c
--- /dev/null
+++ b/python-built-in-functions/menu.py
@@ -0,0 +1,9 @@
+def list_menu(options):
+    print("Main Menu:")
+    for index, option in enumerate(options, start=1):
+        print(f"{index}. {option}")
+
+
+# Example usage
+menu_options = ["Open", "Save", "Settings", "Quit"]
+list_menu(menu_options)
diff --git a/python-built-in-functions/person.py b/python-built-in-functions/person.py
new file mode 100644
index 0000000000..908949f854
--- /dev/null
+++ b/python-built-in-functions/person.py
@@ -0,0 +1,9 @@
+class Person:
+    def __init__(self, name, age):
+        self.name = name
+        self.age = age
+
+
+jane = Person("Jane", 25)
+print(getattr(jane, "name"))
+print(getattr(jane, "age"))
diff --git a/python-built-in-functions/point.py b/python-built-in-functions/point.py
new file mode 100644
index 0000000000..8163bd89bb
--- /dev/null
+++ b/python-built-in-functions/point.py
@@ -0,0 +1,14 @@
+import math
+
+
+class Point:
+    def __init__(self, x, y):
+        self.x = x
+        self.y = y
+
+    @classmethod
+    def from_polar(cls, distance, angle):
+        return cls(
+            x=distance * math.cos(math.radians(angle)),
+            y=distance * math.sin(math.radians(angle)),
+        )
diff --git a/python-built-in-functions/point_v1.py b/python-built-in-functions/point_v1.py
new file mode 100644
index 0000000000..06174f2b46
--- /dev/null
+++ b/python-built-in-functions/point_v1.py
@@ -0,0 +1,27 @@
+# class Point:
+#     def __init__(self, x, y):
+#         self.x = x
+#         self.y = y
+
+
+class Point:
+    def __init__(self, x, y):
+        self.set_x(x)
+        self.set_y(y)
+
+    def get_x(self):
+        return self._x
+
+    def set_x(self, x):
+        self._x = self.validate(x)
+
+    def get_y(self):
+        return self._y
+
+    def set_y(self, y):
+        self._y = self.validate(y)
+
+    def validate(self, value):
+        if not isinstance(value, int | float):
+            raise ValueError("coordinates must be numbers")
+        return value
diff --git a/python-built-in-functions/point_v2.py b/python-built-in-functions/point_v2.py
new file mode 100644
index 0000000000..d077ae0fba
--- /dev/null
+++ b/python-built-in-functions/point_v2.py
@@ -0,0 +1,25 @@
+class Point:
+    def __init__(self, x, y):
+        self.x = x
+        self.y = y
+
+    @property
+    def x(self):
+        return self._x
+
+    @x.setter
+    def x(self, value):
+        self._x = self.validate(value)
+
+    @property
+    def y(self):
+        return self._y
+
+    @y.setter
+    def y(self, value):
+        self._y = self.validate(value)
+
+    def validate(self, value):
+        if not isinstance(value, int | float):
+            raise ValueError("coordinates must be numbers")
+        return value
diff --git a/python-built-in-functions/powers.py b/python-built-in-functions/powers.py
new file mode 100644
index 0000000000..1519bc3cd7
--- /dev/null
+++ b/python-built-in-functions/powers.py
@@ -0,0 +1,13 @@
+import timeit
+
+base = 2
+exp = 1000000
+mod = 1000000
+
+print(
+    timeit.timeit("pow(base, exp) % mod", globals=globals(), number=10) * 1000
+)
+
+print(
+    timeit.timeit("pow(base, exp, mod)", globals=globals(), number=10) * 1000
+)
diff --git a/python-built-in-functions/processors.py b/python-built-in-functions/processors.py
new file mode 100644
index 0000000000..5858e2fb64
--- /dev/null
+++ b/python-built-in-functions/processors.py
@@ -0,0 +1,45 @@
+import csv
+import json
+
+
+class CSVProcessor:
+    def __init__(self, filename):
+        self.filename = filename
+
+    def read(self):
+        with open(self.filename, encoding="utf-8", newline="") as file:
+            return list(csv.DictReader(file))
+
+    def write(self, data):
+        with open(
+            self.filename, mode="w", encoding="utf-8", newline=""
+        ) as file:
+            writer = csv.DictWriter(file, fieldnames=data[0].keys())
+            writer.writeheader()
+            writer.writerows(data)
+
+
+class JSONProcessor:
+    def __init__(self, filename):
+        self.filename = filename
+
+    def read(self):
+        with open(self.filename, encoding="utf-8") as file:
+            return json.load(file)
+
+    def write(self, data):
+        with open(self.filename, mode="w", encoding="utf-8") as file:
+            json.dump(data, file, indent=2)
+
+
+class FileProcessor:
+    def __init__(self, filename, processor):
+        self.filename = filename
+        self.processor = processor(filename)
+
+    def __getattr__(self, attr):
+        return getattr(self.processor, attr)
+
+
+file_proc = FileProcessor("products.csv", CSVProcessor)
+print(file_proc.read())
diff --git a/python-built-in-functions/products.csv b/python-built-in-functions/products.csv
new file mode 100644
index 0000000000..a0e6ee10d1
--- /dev/null
+++ b/python-built-in-functions/products.csv
@@ -0,0 +1,6 @@
+product,price,sold_units
+Laptop,1200,30
+Phone,700,50
+Tablet,450,100
+Desktop,1000,20
+Monitor,300,50
\ No newline at end of file
diff --git a/python-built-in-functions/progress.py b/python-built-in-functions/progress.py
new file mode 100644
index 0000000000..58f7a7a672
--- /dev/null
+++ b/python-built-in-functions/progress.py
@@ -0,0 +1,16 @@
+def progress(percent=0, width=30):
+    end = ""
+    if percent == 100:
+        end = "\n"
+    left = width * percent // 100
+    right = width - left
+    print(
+        "\r[",
+        "#" * left,
+        " " * right,
+        "]",
+        f" {percent:.0f}%",
+        sep="",
+        end=end,
+        flush=True,
+    )
diff --git a/python-built-in-functions/reader.py b/python-built-in-functions/reader.py
new file mode 100644
index 0000000000..638bf6d887
--- /dev/null
+++ b/python-built-in-functions/reader.py
@@ -0,0 +1,7 @@
+def read_user_input():
+    print("Enter word (type 'done' to finish):")
+    for word in iter(input, "done"):
+        print(f"Processing word: '{word}'")
+
+
+read_user_input()
diff --git a/python-built-in-functions/shapes.py b/python-built-in-functions/shapes.py
new file mode 100644
index 0000000000..2c1c871552
--- /dev/null
+++ b/python-built-in-functions/shapes.py
@@ -0,0 +1,15 @@
+class Rectangle:
+    def __init__(self, length, width):
+        self.length = length
+        self.width = width
+
+    def area(self):
+        return self.length * self.width
+
+    def perimeter(self):
+        return 2 * (self.length + self.width)
+
+
+class Square(Rectangle):
+    def __init__(self, length):
+        super().__init__(length, length)
diff --git a/python-built-in-functions/stack.py b/python-built-in-functions/stack.py
new file mode 100644
index 0000000000..52b42f8a1a
--- /dev/null
+++ b/python-built-in-functions/stack.py
@@ -0,0 +1,12 @@
+class Stack:
+    def __init__(self, items=None):
+        self.items = list(items) if items is not None else []
+
+    def push(self, item):
+        self.items.append(item)
+
+    def pop(self):
+        return self.items.pop()
+
+    def __bool__(self):
+        return bool(self.items)
diff --git a/python-built-in-functions/uppercase.py b/python-built-in-functions/uppercase.py
new file mode 100644
index 0000000000..b4b8252a76
--- /dev/null
+++ b/python-built-in-functions/uppercase.py
@@ -0,0 +1,9 @@
+def is_uppercase(text):
+    for char in text:
+        if not (65 <= ord(char) <= 90):
+            return False
+    return True
+
+
+print(is_uppercase("HELLO"))  # True
+print(is_uppercase("Hello"))  # False

From 157a12f3e4f563703776b32c9683c8d26161d954 Mon Sep 17 00:00:00 2001
From: Leodanis Pozo Ramos <lpozor78@gmail.com>
Date: Mon, 3 Jun 2024 20:12:51 +0200
Subject: [PATCH 2/3] Fix the linter issues

---
 python-built-in-functions/calculations.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/python-built-in-functions/calculations.py b/python-built-in-functions/calculations.py
index a2a2e46e5f..03694ace8b 100644
--- a/python-built-in-functions/calculations.py
+++ b/python-built-in-functions/calculations.py
@@ -10,7 +10,8 @@
     exec(function)
 
 
-add(1, 2)
-subtract(3, 2)
-multiply(2, 3)
-divide(6, 3)
+# Uncomment the following lines
+# print(add(1, 2))
+# print(subtract(3, 2))
+# print(multiply(2, 3))
+# print(divide(6, 3))

From 58ff37971d8eb6c72d269526b9cd417af0b9e6f9 Mon Sep 17 00:00:00 2001
From: Leodanis Pozo Ramos <lpozor78@gmail.com>
Date: Wed, 12 Jun 2024 17:49:52 +0200
Subject: [PATCH 3/3] TR update, first round

---
 python-built-in-functions/invert.py | 20 --------------------
 1 file changed, 20 deletions(-)
 delete mode 100644 python-built-in-functions/invert.py

diff --git a/python-built-in-functions/invert.py b/python-built-in-functions/invert.py
deleted file mode 100644
index 9320b2c726..0000000000
--- a/python-built-in-functions/invert.py
+++ /dev/null
@@ -1,20 +0,0 @@
-def invert_case(text):
-    result = ""
-    shift = ord("a") - ord("A")
-
-    for char in text:
-        code_point = ord(char)
-        if char.islower():
-            result += chr(code_point - shift)
-        elif char.isupper():
-            result += chr(code_point + shift)
-        else:
-            result += char
-
-    return result
-
-
-# Example usage
-example_string = "Hello, World!"
-print("Original:", example_string)
-print("Inverted Case:", invert_case(example_string))