ImportError: cannot import name (not a circular dependency)

Question

I have the problem on importing the class in the same package, and it seems not a circular dependency problem. So I'm really confused now.

my-project/
   lexer.py
   exceptions.py

I declared an exception in exceptions.py and wants to use it in lexer.py:

exceptions.py:

class LexError(Exception):
    def __init__(self, message, line):
        self.message = message
        self.line = line

and in lexer.py:

import re
import sys

from exceptions import LexError
...

It shouldn't be circular dependency since lexer.py is the only file has import in it.

Thanks!!

Answer 1

exceptions conflicts with builtin module exception.

>>> import exceptions
>>> exceptions.LexError
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'module' object has no attribute 'LexError'
>>> from exceptions import LexError
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: cannot import name LexError

Use different module name.