Reference library

Dictionaries & sets

Key–value maps, uniqueness, counting, grouping, and fast lookups.

28 matches

How to Validate Required Dict Keys in Python

Check whether a dictionary contains all required keys and return the list of missing ones using a simple list comprehension.

dictionary validation missing-keys

Python

def find_missing_keys(data: dict, required_keys: list) -> list:
    """Return a list of required keys that are missing from the dictionary."""
    return [key for key in required_keys if key not in data]


if __name__ == "__main__":
    user_data = {
        "name": "Alice",
        "email": "alice@example.com",
     …

12 0 Open

Dictionaries & sets easy

How to convert string values to int or float in Python dicts

Recursively convert string values in nested dicts and lists to ints or floats when possible, leaving other strings untouched.

dict type-conversion recursion

Python

def coerce_str_values(data):
    """Recursively convert string values that look like ints or floats."""
    if isinstance(data, dict):
        return {key: coerce_str_values(val) for key, val in data.items()}
    elif isinstance(data, list):
        return [coerce_str_values(item) for item in data]
    elif isinstance…

12 0 Open

Dictionaries & sets easy

Parse Env Vars into Typed Dict in Python

Convert a list of environment variable names into a dictionary with automatically detected types (bool, int, float, or string), defaulting missing vars to None.

env-vars type-conversion dict

Python

import os
from typing import Any, Dict


def parse_env_vars(env_names: list[str], env: Dict[str, str] | None = None) -> Dict[str, Any]:
    """Parse a list of environment variable names into a typed dict.

    Each variable is parsed as:
    - bool: "true"/"false" (case-insensitive)
    - int: if it can be converted t…

13 0 Open

Dictionaries & sets easy

Validate dictionary data with sets in Python

Validate a dictionary against required keys and allowed value sets, returning a list of validation errors.

dictionaries sets validation

Python

def validate_data(data, required_keys, allowed_values=None):
    """
    Validate a dictionary against required keys and optional allowed value sets.
    Returns a list of validation errors (empty list if valid).
    """
    errors = []
    
    # Check for missing required keys
    missing = set(required_keys) - set(…

14 0 Open

Browse by section

Each section groups closely related Python snippets.