问题是您正在script.py内部运行custom.class2，这意味着在运行custom.class2时，您仍位于root目录中

The problem is that you are running custom.class2 inside of script.py, which means while running custom.class2, you are still in the root directory.

要解决此问题，应将class2.py中的from class1 import Class1替换为from custom.class1 import Class1.

To fix this, you should replace from class1 import Class1 from class2.py with from custom.class1 import Class1.

如果您需要能够从任何工作目录中运行文件，则可以用以下内容替换其内容:

If you need to be able to run the file from any working directory, you may replace it's contents with this:

import os
import sys

path = os.path.abspath(os.path.dirname(__file__))
if not path in sys.path:
    sys.path.append(path)

from class1 import Class1

class Class2():
    def __init__(self):
        cl1 = Class1()
        print('Class2')

if __name__ == '__main__':
    cl2 = Class2()

代码将文件的路径添加到sys.path列表中，该列表包含可从中导入模块的不同路径.

The code adds the file's path in to the sys.path list, which holds different paths from which you can import modules.