一、Python高级特性

1.1 上下文管理器与with语句

# 自定义上下文管理器
class DatabaseConnection:
 def __enter__(self):
 self.conn = create_connection()
 return self.conn
 
 def __exit__(self, exc_type, exc_val, exc_tb):
 self.conn.close()
 
# 使用上下文管理器
with DatabaseConnection() as conn:
 conn.execute_query("SELECT * FROM users")

1.2 生成器与协程

# 生成器表达式
squares = (x*x for x in range(10000))
# 协程
def coroutine():
 while True:
 received = yield
 print(f"Received: {received}")
# 使用协程
c = coroutine()
next(c) # 预激协程
c.send("Hello")