Reference library

Python Code Samples

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

7 matches
Data pipelines & processing easy

Validate dict schema at pipeline boundary in Python

This code validates a dictionary against a TypedDict schema at a pipeline boundary, enforcing required fields and types with custom error messages.

validation dict typeddict
Python
from typing import Any, TypedDict


class Person(TypedDict):
    name: str
    age: int
    email: str


def validate_person(data: dict[str, Any]) -> Person:
    errors: list[str] = []

    if not isinstance(data.get("name"), str) or not data["name"].strip():
        errors.append("name must be a non-empty string")
  …
12 0 Open
Modern tooling easy

How to Type Check a Mock with pyright in Python

Shows how pyright validates a mock function against a TypedDict and Callable signature before runtime.

pyright type-checking mocking
Python
from typing import TypedDict, Callable


class User(TypedDict):
    id: int
    name: str


def get_user_name(user_id: int, get_user: Callable[[int], User]) -> str:
    user = get_user(user_id)
    return user["name"]


def mock_get_user(user_id: int) -> User:
    return {"id": user_id, "name": f"User {user_id}"}


if…
14 0 Open
Testing & modern typing easy

Design Data Helpers with Python TypedDict and Literal

Use TypedDict, Literal, and Union to define typed data shapes and parse values in Python.

typeddict literal union
Python
from typing import TypedDict, Literal, Optional, Union, List

class User(TypedDict):
    name: str
    age: int
    role: Literal["admin", "user", "guest"]

def describeUser(data: User) -> str:
    return f"{data['name']} ({data['age']}) — {data['role']}"

def parse_value(item: Union[int, str, None]) -> str:
    if it…
12 0 Open
Testing & modern typing easy

How to Merge TypedDicts in Python

Merge two TypedDict dictionaries with type-aware logic using NotRequired, **kwargs unpacking, and safe key updates.

typing typeddict dict
Python
from typing import TypedDict, NotRequired, merge  # hypothetical

class User(TypedDict):
    name: str
    email: NotRequired[str]
    age: NotRequired[int]

def merge_users(base: User, **overrides: User) -> User:
    """Merge two user dicts with typing-aware logic."""
    result: User = dict(base)
    for key, value …
13 0 Open
Testing & modern typing easy

How to Use TypedDict and Dataclasses in Python

Create typed data structures with TypedDict and dataclasses, then use them as helper functions for describing objects in a type-safe way.

typing typdict dataclass
Python
from typing import TypedDict, NotRequired, Optional
from dataclasses import dataclass


class User(TypedDict):
    name: str
    age: NotRequired[int]
    email: Optional[str]


@dataclass
class Product:
    id: int
    title: str
    price: float = 0.0


def describe_user(user: User) -> str:
    age = user.get("age",…
11 0 Open
Testing & modern typing medium

How to Use TypedDict for Data Validation in Python

Define a TypedDict schema and validate raw dictionary input with type hints for safer, more readable data handling.

typeddict typing validation
Python
from typing import Any, Dict, List, Optional, Union, TypedDict, Literal

class Product(TypedDict):
    product_id: int
    name: str
    price: Union[int, float]
    in_stock: bool
    tags: Optional[List[str]]

def validate_product(data: Dict[str, Any]) -> Product:
    product_id: int = int(data["product_id"])
    na…
13 0 Open
Testing & modern typing easy

How to Use TypedDict for Structured Dict Typing in Python

Define and use TypedDict to add type hints to dictionaries, improving code clarity and enabling static type checking in your Python projects.

typing typeddict type-hints
Python
from typing import TypedDict


class User(TypedDict):
    name: str
    age: int
    email: str


def greet(user: User) -> str:
    return f"Hello {user['name']}, age {user['age']}, contact {user['email']}"


if __name__ == "__main__":
    alice: User = {"name": "Alice", "age": 30, "email": "alice@example.com"}
    pr…
11 0 Open

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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.