Explain the difference between FastAPI and Flask.

beginner

Re-explain

Key differences:

FastAPI	Flask
ASGI-based (async)	WSGI-based (sync by default)
Built-in type validation	Manual validation required
Automatic API documentation	Requires extensions
Modern Python features	More traditional approach
Better performance	Simpler for basic apps
Pydantic integration	No built-in serialization

FastAPI is better for modern APIs requiring high performance and automatic documentation, while Flask offers more flexibility and simplicity for traditional web applications.

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