Merge remote-tracking branch 'origin/2025-learn'

Author: egges

2025/learn/1_master_core.py

@@ -0,0 +1,16 @@
+def main() -> None:
+    words = ["code", "python", "ai", "refactor", "bug"]
+
+    length_map: dict[str, int] = {}
+    for word in words:
+        if len(word) > 4:
+            length_map[word] = len(word)
+
+    print(length_map)
+
+    # now with a dict comprehension
+    length_map_comp = {word: len(word) for word in words if len(word) > 4}
+    print(length_map_comp)
+
+if __name__ == "__main__":
+    main()

2025/learn/2_pythonic.py

@@ -0,0 +1,12 @@
+def main() -> None:
+    names = ["Arjan", "Marieke", "Pim", "Sanne", "Daan", "Eva", "Lars"]
+
+    for i in range(len(names)):
+        print(i, names[i])
+
+    # or more pythonic
+    for index, name in enumerate(names):
+        print(index, name)
+
+if __name__ == "__main__":
+    main()

2025/learn/3_build_tools.py

@@ -0,0 +1,5 @@
+from pathlib import Path
+
+def rename_jpegs(folder: str):
+    for file in Path(folder).glob("*.jpeg"):
+        file.rename(file.with_suffix(".jpg"))

2025/learn/4_object_model.py

@@ -0,0 +1,10 @@
+def greet(name: str) -> str:
+    return f"Hello, {name}!"
+
+def main() -> None:
+    say_hello = greet
+
+    print(say_hello("Pythonista"))
+
+if __name__ == "__main__":
+    main()

2025/learn/5_types_abstraction.py

@@ -0,0 +1,14 @@
+from typing import Protocol, Callable
+
+class Logger(Protocol):
+    def info(self, message: str) -> None: ...
+    def error(self, message: str) -> None: ...
+
+def process_order(order_id: int, logger: Logger) -> None:
+    logger.info(f"Processing order {order_id}")
+
+
+ImageExporter = Callable[[bytes], None]
+
+def export_image(data: bytes, exporter: ImageExporter) -> None:
+    exporter(data)

2025/learn/6_design.py

@@ -0,0 +1,42 @@
+from typing import Protocol
+
+def notify_user_no_di(user_email: str, message: str):
+    print(f"Sending email to {user_email}: {message}")
+
+
+# Define a Protocol (interface) for notification services
+class Notifier(Protocol):
+    def send(self, recipient: str, message: str) -> None:
+        ...
+
+
+# Concrete implementation: sends email
+class EmailNotifier:
+    def send(self, recipient: str, message: str) -> None:
+        print(f"[Email] To: {recipient} | Message: {message}")
+
+
+# Concrete implementation: sends SMS
+class SMSNotifier:
+    def send(self, recipient: str, message: str) -> None:
+        print(f"[SMS] To: {recipient} | Message: {message}")
+
+
+# Business logic function with injected dependency
+def notify_user(user: str, message: str, notifier: Notifier) -> None:
+    notifier.send(user, message)
+
+
+def main() -> None:
+    email_notifier = EmailNotifier()
+    sms_notifier = SMSNotifier()
+
+    # Send email
+    notify_user("alice@example.com", "Your invoice is ready.", email_notifier)
+
+    # Send SMS
+    notify_user("+31612345678", "Your package is on the way!", sms_notifier)
+
+
+if __name__ == "__main__":
+    main()

2025/learn/7_testing.py

@@ -0,0 +1,31 @@
+import pytest
+import sys
+
+# Function we want to test
+def is_prime(n: int) -> bool:
+    if n <= 1:
+        return False
+    for i in range(2, int(n**0.5) + 1):
+        if n % i == 0:
+            return False
+    return True
+
+
+# Parametrized test: tests multiple inputs in one go
+@pytest.mark.parametrize("n, expected", [
+    (2, True),
+    (3, True),
+    (4, False),
+    (17, True),
+    (18, False),
+    (1, False),
+    (0, False),
+    (-5, False),
+])
+def test_is_prime(n: int, expected: bool) -> None:
+    assert is_prime(n) == expected
+
+
+# Optional: run pytest programmatically from the same file
+if __name__ == "__main__":
+    sys.exit(pytest.main([__file__]))

2025/learn/8_internals.py

@@ -0,0 +1,20 @@
+class Countdown:
+    def __init__(self, start: int):
+        self.current = start
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        if self.current <= 0:
+            raise StopIteration
+        self.current -= 1
+        return self.current + 1
+    
+def main() -> None:
+    countdown = Countdown(5)
+    for number in countdown:
+        print(number)
+
+if __name__ == "__main__":
+    main()

2025/learn/9_standard.py

@@ -0,0 +1,9 @@
+import textwrap
+
+
+def main() -> None:
+    text = "This is a sample text that will be wrapped to a specified width using the textwrap module in Python."
+    print(textwrap.fill(text, width=40))
+
+if __name__ == "__main__":
+    main()

2025/learn/pyproject.toml

@@ -0,0 +1,7 @@
+[project]
+name = "learning_python"
+version = "0.1.0"
+requires-python = ">=3.13"
+dependencies = [
+    "pytest>=8.4.2",
+]