Here is a simplified example that exhibits the problem.

Parent is the parent package to sub-packages A and B.

Sub-Package A: Parent/A/__init__.py contains "import a" Parent/A/a.py contains:

from __future__ import absolute_import
from ..B import b
class aClass(b.bClass):

  def __init__(self):
      b.bClass.__init__(self)

  def foo(self):
      print self.x
      print self.y
      print self.z

Sub-Package B: Parent/B/__init__.py contains "import b" Parent/B/b.py contains:

class bClass:

  def __init__(self):
      self.x = 0
      self.y = []
      self.z = ''

The Parent package is located in my sys.path. The above code runs just fine:

>>> import Parent.A
>>> a = Parent.A.a.aClass(1)
>>> a.foo()
0

However, when I run pylint for A/a.py it gives me

F0401:  9: Unable to import 'B.b' (No module named B)

and therefore of course the ensuing errors:

E1101: 14:aClass.foo: Instance of 'aClass' has no 'x' member E1101: 15:aClass.foo: Instance of 'aClass' has no 'y' member E1101: 16:aClass.foo: Instance of 'aClass' has no 'z' member

If I change the import syntax in Parent/A/a.py to use "from Parent.B import b" all errors go away. This seems to indicate a problem with intra-sub-package relative imports.