Python3.x load module path error

[daidai21]

Python3.x load module path error

Program execute display like this error: ImportError: No module named 'xxx' also you used like this code: from .xxx import xxx or from ..xxx import xxx.

Example:

• module/
  • __init__.py
  • A/
    • __init__.py
    • a.py

      def func():
          print("A.a")

  • B/
    • __init__.py
    • b.py

      from ..A.a import func
      
      func()

• main.py

  from module.B import *

This code will display error when running python3 b.py. I think maybe Python3 Interpreter not support this grammar.
And code will display error when running python3 main.py. if you use sys.paths.append("../") or sys.paths.append("./") like this code, still a mistake. Because program when load module abspath is main.py file, not b.py file. And C++ /C language is not such.

Solve Method

• __file__ return current file path
• os.path.abspath(path) return file abspath
• os.path.dirname() return folder abspath
• os.path.join() join path

load one level catalog path: os.path.abspath(os.path.join(os.path.dirname(__file__), "../")), load two level catalog path: os.path.abspath(os.path.join(os.path.dirname(__file__), "../../")), etc.