app/utils/helpers.py

import os
from pathlib import Path

def ensure_directory(path: str):
    Path(path).mkdir(parents=True, exist_ok=True)

def get_file_extension(filename: str) -> str:
    return os.path.splitext(filename)[1].lower()

def is_valid_image_extension(extension: str) -> bool:
    from app.core.config import settings
    return extension in settings.ALLOWED_EXTENSIONS