Mac下Jupyter Notebook中Pythonnet调用C#异常无输出且内核挂起

问题现象 #

• 使用pythonnet在Python中调用C#函数时，Jupyter Notebook中一旦触发错误，内核会无限挂起且无任何错误信息输出
• 终端运行相同Python脚本时，能正常捕获错误信息并终止进程
• Windows环境下的团队成员在Jupyter Notebook中无此问题，推测与macOS操作系统相关
• 传入合法参数时Jupyter Notebook可正常输出结果，仅在出错时出现内核挂起

环境信息 #

• 操作系统：macOS Ventura 13.6（M1芯片）
• VS 2022
• Python 3.9.12
• IPython 8.0.0
• jupyter_client 7.4.9
• jupyter_core 5.3.0
• jupyter_server 2.5.0

示例代码 #

C#项目代码（HelloWorld） #

// Project HelloWorld
namespace MyLibrary
{
    public class Adder
    {
        public int Add(int left, int right)
        {
            return left + right;
        }
        public static void Main(string[] args)
        { }
   }
}

Python调用代码 #

from clr_loader import get_coreclr
from pathlib import Path
from pythonnet import set_runtime
from os.path import abspath

# 设置已发布的C#项目路径
libfolder = Path(abspath("")) / "lib"
set_runtime(get_coreclr(runtime_config=libfolder / "clr_runtime.json"))
import clr
clr.AddReference(str((libfolder / "HelloWorld").absolute()))

from MyLibrary import Adder

adder = Adder()
print(f"My C# Adder method: {adder.Add(3.2, 4)}") # 传入float而非int触发错误

错误表现对比 #

终端运行结果（正常输出错误） #

Python.Runtime.PythonException: an integer is required

The above exception was the direct cause of the following exception:

System.ArgumentException: an integer is required in method Int32 Add(Int32, Int32)
 ---> Python.Runtime.PythonException: an integer is required
   --- End of inner exception stack trace ---

The above exception was the direct cause of the following exception:

System.AggregateException: One or more errors occurred. (an integer is required in method Int32 Add(Int32, Int32))
 ---> System.ArgumentException: an integer is required in method Int32 Add(Int32, Int32)
 ---> Python.Runtime.PythonException: an integer is required
   --- End of inner exception stack trace ---
   --- End of inner exception stack trace ---

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/Users/virgfrey/Projects/Hello World/test.py", line 17, in <module>
    print(f"My C# Adder method: {adder.Add(3.2,4)}")
TypeError: No method matches given arguments for Adder.Add: (<class 'float'>, <class 'int'>)

Jupyter Notebook运行结果 #

内核无限挂起，无任何错误信息输出

临时解决方案 #

• 提前参数校验：在调用C#函数前，对传入参数的类型、取值范围做校验，从源头避免触发错误
• 捕获异常并强制终止：在Python代码中添加try-except块，捕获异常后主动终止内核进程（仅适用于测试阶段），示例：

try:
    print(f"My C# Adder method: {adder.Add(3.2, 4)}")
except Exception as e:
    print(f"Error occurred: {e}")
    # 强制终止内核
    import os
    os._exit(1)

• 升级依赖版本：尝试将IPython、jupyter相关包以及pythonnet更新至最新稳定版，排查是否为旧版本兼容性问题导致的异常处理失效

内容的提问来源于stack exchange，提问作者Virginia