接口——类比摄像
最近迷上了买相机，大疆Pocket、Insta Go3、大疆Mini3、佳能50D、vivo徕卡人像大师（狗头），在买配件的时候，发现1/4螺口简直是神中之神，这个万能接口让我想到计算机设计中的接口，遂有此篇——
接口的代码格式因编程语言而异，下面提供两个经典接口的示例，分别是 REST API 和 gRPC，并对比它们的区别。
- REST API 示例（Python Flask）
REST API 使用 HTTP 协议，通过不同的 HTTP 方法（GET、POST、PUT、DELETE）操作资源，返回 JSON 或 XML 格式的数据。
from flask import Flask, jsonify, requestapp = Flask(__name__)# 模拟数据
books = [{"id": 1, "title": "Python Crash Course", "author": "Eric Matthes"},{"id": 2, "title": "Clean Code", "author": "Robert C. Martin"}
]# 获取所有书籍
@app.route('/api/books', methods=['GET'])
def get_books():return jsonify(books)# 获取单个书籍
@app.route('/api/books/<int:book_id>', methods=['GET'])
def get_book(book_id):book = next((b for b in books if b['id'] == book_id), None)if book is None:return jsonify({"error": "Book not found"}), 404return jsonify(book)# 添加书籍
@app.route('/api/books', methods=['POST'])
def add_book():data = request.get_json()new_book = {"id": len(books) + 1,"title": data.get('title'),"author": data.get('author')}books.append(new_book)return jsonify(new_book), 201if __name__ == '__main__':app.run(debug=True)
- gRPC 示例（Python + Protocol Buffers）
gRPC 使用 Protocol Buffers 定义服务和消息格式，通过 HTTP/2 进行通信，提供强类型接口和高性能。
首先定义 .proto 文件（book.proto）：
syntax = "proto3";package book;// 定义消息格式
message Book {int32 id = 1;string title = 2;string author = 3;
}message BookRequest {int32 id = 1;
}message BookList {repeated Book books = 1;
}// 定义服务接口
service BookService {// 获取所有书籍rpc GetBooks(google.protobuf.Empty) returns (BookList);// 获取单个书籍rpc GetBook(BookRequest) returns (Book);// 添加书籍rpc AddBook(Book) returns (Book);
}
然后实现服务端（server.py）：
import grpc
from concurrent import futures
import book_pb2
import book_pb2_grpcclass BookService(book_pb2_grpc.BookServiceServicer):def __init__(self):self.books = [book_pb2.Book(id=1, title="Python Crash Course", author="Eric Matthes"),book_pb2.Book(id=2, title="Clean Code", author="Robert C. Martin")]def GetBooks(self, request, context):return book_pb2.BookList(books=self.books)def GetBook(self, request, context):for book in self.books:if book.id == request.id:return bookcontext.set_code(grpc.StatusCode.NOT_FOUND)return book_pb2.Book()def AddBook(self, request, context):new_book = book_pb2.Book(id=len(self.books) + 1,title=request.title,author=request.author)self.books.append(new_book)return new_bookdef serve():server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))book_pb2_grpc.add_BookServiceServicer_to_server(BookService(), server)server.add_insecure_port('[::]:50051')server.start()print("Server started, listening on port 50051")server.wait_for_termination()if __name__ == '__main__':serve()
幼儿园版
