</>
pythonintermediate

Protocol

Advanced Python pattern: protocol

python
from typing import Protocol

class SupportsLen(Protocol):
    def __len__(self) -> int: ...

def has_items(x: SupportsLen) -> bool:
    return len(x) > 0

print(has_items([1, 2, 3]))

Use Cases

  • advanced programming
  • patterns

Tags

#python#advanced#protocol

Related Snippets

Similar patterns you can reuse in the same workflow.

pythonintermediate

Implement the Iterator Protocol

Create custom iterators using __iter__ and __next__ for lazy evaluation.

Best for: Batch processing

#python#iterator
pythonadvanced

Protocol Classes for Structural Typing

Define interfaces with Protocol for duck-typing that works with static type checkers.

Best for: dependency injection

#python#protocol
pythonbeginner

Type Hints

Advanced Python pattern: type-hints

Best for: advanced programming

#python#advanced
pythonintermediate

Dataclass

Advanced Python pattern: dataclass

Best for: advanced programming

#python#advanced