RF: Drop six.*metaclass

Author: effigies

nibabel/cifti2/cifti2_axes.py

@@ -120,7 +120,7 @@
 """
 import numpy as np
 from . import cifti2
-from six import string_types, add_metaclass, integer_types
+from six import string_types, integer_types
 from operator import xor
 import abc
 
@@ -173,8 +173,7 @@ def to_header(axes):
     return cifti2.Cifti2Header(matrix)
 
 
-@add_metaclass(abc.ABCMeta)
-class Axis(object):
+class Axis(abc.ABC):
     """
     Abstract class for any object describing the rows or columns of a CIFTI-2 vector/matrix
 

nibabel/streamlines/tractogram_file.py

@@ -1,7 +1,6 @@
 """  Define abstract interface for Tractogram file classes
 """
-from abc import ABCMeta, abstractmethod
-from six import with_metaclass
+from abc import ABC, abstractmethod
 
 from .header import Field
 
@@ -34,7 +33,7 @@ def __init__(self, callable):
         super(abstractclassmethod, self).__init__(callable)
 
 
-class TractogramFile(with_metaclass(ABCMeta)):
+class TractogramFile(ABC):
     """ Convenience class to encapsulate tractogram file format. """
 
     def __init__(self, tractogram, header=None):

nibabel/tests/test_api_validators.py

@@ -1,8 +1,6 @@
 """ Metaclass and class for validating instance APIs
 """
 
-from six import with_metaclass
-
 from nose.tools import assert_equal
 
 
@@ -32,7 +30,7 @@ def meth(self):
         return klass
 
 
-class ValidateAPI(with_metaclass(validator2test)):
+class ValidateAPI(metaclass=validator2test):
     """ A class to validate APIs
 
     Your job is twofold: