循环导入修复来自pylint的R0401

Question

Pylint抱怨NLTK包的特定文件使用R0401错误代码进行循环导入。

nltk/nltk/ccg/lexicon.py:1: [R0401(cyclic-import), ] Cyclic import (nltk -> nltk.internals)
nltk/nltk/ccg/lexicon.py:1: [R0401(cyclic-import), ] Cyclic import (nltk.corpus -> nltk.tokenize -> nltk.tokenize.punkt -> nltk.probability)
nltk/nltk/ccg/lexicon.py:1: [R0401(cyclic-import), ] Cyclic import (nltk.corpus -> nltk.tokenize -> nltk.tokenize.texttiling)
nltk/nltk/ccg/lexicon.py:1: [R0401(cyclic-import), ] Cyclic import (nltk.draw.tree -> nltk.tree)
nltk/nltk/ccg/lexicon.py:1: [R0401(cyclic-import), ] Cyclic import (nltk.tree -> nltk.treeprettyprinter)
nltk/nltk/ccg/lexicon.py:1: [R0401(cyclic-import), ] Cyclic import (nltk.grammar -> nltk.parse.pchart)
nltk/nltk/ccg/lexicon.py:1: [R0401(cyclic-import), ] Cyclic import (nltk.stem -> nltk.stem.porter)
nltk/nltk/ccg/lexicon.py:1: [R0401(cyclic-import), ] Cyclic import (nltk.classify.maxent -> nltk.classify.tadm)

完整的列表在https://github.com/nltk/nltk/issues/2113上

但从进口来看：

from __future__ import unicode_literals from 

import re
from collections import defaultdict

from nltk.ccg.api import PrimitiveCategory, Direction, CCGVar, FunctionalCategory
from nltk.compat import python_2_unicode_compatible
from nltk.internals import deprecated

from nltk.sem.logic import *

但是看看nltk.internals https://github.com/nltk/nltk/blob/develop/nltk/internals.py，没有任何循环导入指向nltk.ccg.lexicon

from __future__ import print_function

import subprocess
import os
import fnmatch
import re
import warnings
import textwrap
import types
import sys
import stat
import locale

# Use the c version of ElementTree, which is faster, if possible:
try:
    from xml.etree import cElementTree as ElementTree
except ImportError:
    from xml.etree import ElementTree

from six import string_types

from nltk import __file__
from nltk import compat

R0401(cyclic-import) 消息是什么意思？

看看nltk.ccg.lexicon.py和nltk.internals.py，没有任何循环的导入，所以如何解决这个问题。

Answer 1

不确定为什么pylint会在nltk/nltk/ccg/lexicon.py文件中报告这些内容，但是循环导入本身可以在错误消息的右边看到。

第一个错误：Cyclic import (nltk -> nltk.internals)：根.py有一个来自nltk.internals的导入，internals.py有一个来自包根的导入，这显然是一个循环导入。