Reference library

Python Code Samples

Copy-ready Python snippets by topic and difficulty — short, focused, and runnable in the browser editor.

4 matches
OOP & classes medium

Composable Predicates with the &, |, ~ Operators in Python

Define a reusable Predicate class that combines boolean checks with & (AND), | (OR), and ~ (NOT) operators.

predicates operator-overloading oop
Python
class Predicate:
    def __init__(self, func, name=None):
        self.func = func
        self.name = name or getattr(func, "__name__", "predicate")

    def __call__(self, value):
        return self.func(value)

    def __and__(self, other):
        return Predicate(lambda v: self(v) and other(v), f"({self.name} AN…
13 0 Open
Comprehensions & generators easy

How to Filter Data with Predicates in Python

This helper filters a list with a predicate using a list comprehension, plus a lazy generator version that yields matches one by one.

filtering comprehensions generators
Python
def filter_data(data, predicate):
    """Return a list containing only items that pass the predicate."""
    return [item for item in data if predicate(item)]


def filter_data_lazy(data, predicate):
    """Generator version: yields items that pass the predicate one by one."""
    for item in data:
        if predicat…
16 0 Open
Comprehensions & generators medium

How to filter a generator with a predicate function in Python

This code defines a generator function that yields only items from an iterable that satisfy a given predicate, then tests it with even and positive number filters.

generators filtering lazy evaluation
Python
def filter_gen(predicate, iterable):
    for item in iterable:
        if predicate(item):
            yield item

def is_even(num):
    return num % 2 == 0

def is_positive(num):
    return num > 0

if __name__ == "__main__":
    numbers = range(-5, 10)
    
    even_numbers = list(filter_gen(is_even, numbers))
    p…
10 0 Open
Testing & modern typing easy

How to Filter Data in Python with Type Hints

A reusable filter_data helper uses optional predicates and numeric bounds with modern Python type hints.

filtering type-hints generics
Python
from typing import Iterable, TypeVar, Callable, Any

T = TypeVar("T")

def filter_data(
    items: Iterable[T],
    predicate: Callable[[T], bool] | None = None,
    *,
    min_value: float | None = None,
    max_value: float | None = None,
) -> list[T]:
    """Filter items by predicate and/or numeric bounds."""
    r…
11 0 Open

Browse by section

Each section groups closely related Python snippets.

Guide: free Python code samples library

Copy-ready Python snippets for learners and developers

PythonSkillset code samples are short, focused examples organised by topic and difficulty. Every snippet is server-rendered HTML — readable by search engines and easy to copy. Open any sample, read the notes, copy the code, then press Try in editor to run it in the browser with Pyodide.

How to use this library

  1. Pick a topic section — strings, lists, files, functions, and more
  2. Open a sample, read How it works, and copy the code block
  3. Run it in the IDE, tweak values, then take a related quiz or tutorial lesson

Samples vs tutorials and challenges

Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.