RF: make six dependency, remove OrderedDict module

Depend on six, use six directly, test deprecated nibabel.externals.six
import.

Remove implementation of OrderedDict for Python 2.6, but leave shim in
place, presumably it will die a natural death.

Note that, we can't test six==1.3 as a dependency, because setuptools
needs something later already.

Author: matthew-brett

.travis.yml

@@ -20,7 +20,7 @@ addons:
       - libatlas-base-dev
 env:
     global:
-        - DEPENDS="numpy scipy matplotlib h5py pillow"
+        - DEPENDS="six numpy scipy matplotlib h5py pillow"
         - PYDICOM=1
         - INSTALL_TYPE="setup"
         - EXTRA_WHEELS="https://5cf40426d9f06eb7461d-6fe47d9331aba7cd62fc36c7196769e4.ssl.cf2.rackcdn.com"
@@ -37,7 +37,7 @@ matrix:
     # Absolute minimum dependencies
     - python: 2.7
       env:
-        - DEPENDS=numpy==1.6.0 PYDICOM=0
+        - DEPENDS="numpy==1.6.0" PYDICOM=0
     # Absolute minimum dependencies plus oldest MPL
     # Check these against:
     # nibabel/info.py

bin/nib-ls

@@ -19,11 +19,9 @@ import numpy as np
 import nibabel as nib
 
 from math import ceil
-from collections import defaultdict
 from optparse import OptionParser, Option
 from io import StringIO
 from nibabel.py3k import asunicode
-from nibabel.externals.six.moves import xrange
 
 __author__ = 'Yaroslav Halchenko'
 __copyright__ = 'Copyright (c) 2011-2016 Yaroslav Halchenko ' \

doc/source/installation.rst

@@ -88,6 +88,7 @@ Requirements
 
 *  Python_ 2.7, or >= 3.4
 *  NumPy_ 1.6 or greater
+*  Six_ 1.3 or greater
 *  SciPy_ (optional, for full SPM-ANALYZE support)
 *  PyDICOM_ 0.9.7 or greater (optional, for DICOM support)
 *  `Python Imaging Library`_ (optional, for PNG conversion in DICOMFS)

nibabel/affines.py

@@ -5,7 +5,7 @@
 
 import numpy as np
 
-from .externals.six.moves import reduce
+from six.moves import reduce
 
 
 class AffineError(ValueError):

nibabel/benchmarks/bench_load_save.py

@@ -19,7 +19,7 @@
 
 import numpy as np
 
-from ..externals.six import BytesIO
+from six import BytesIO
 
 from .. import Nifti1Image
 

nibabel/benchmarks/bench_streamlines.py

@@ -17,7 +17,7 @@
 
 import numpy as np
 
-from nibabel.externals.six.moves import zip
+from six.moves import zip
 from nibabel.tmpdirs import InTemporaryDirectory
 
 from numpy.testing import assert_array_equal

nibabel/data.py

@@ -8,7 +8,7 @@
 from os.path import join as pjoin
 import glob
 import sys
-from .externals.six.moves import configparser
+from six.moves import configparser
 from distutils.version import LooseVersion
 
 from .environment import get_nipy_user_dir, get_nipy_system_dir

nibabel/dft.py

@@ -22,7 +22,7 @@
 
 import numpy
 
-from .externals.six import BytesIO
+from six import BytesIO
 
 from .nifti1 import Nifti1Header
 

nibabel/eulerangles.py

@@ -85,7 +85,7 @@
 
 import math
 
-from .externals.six.moves import reduce
+from six.moves import reduce
 
 import numpy as np
 

nibabel/externals/__init__.py

@@ -1,5 +1,5 @@
 # init for externals package
-try:
-    from collections import OrderedDict
-except ImportError:  # < Python 2.7
-    from .ordereddict import OrderedDict
+from collections import OrderedDict
+
+from ..deprecated import ModuleProxy as _ModuleProxy
+six = _ModuleProxy('nibabel.externals.six')

nibabel/externals/netcdf.py

@@ -35,13 +35,13 @@
 from operator import mul
 from mmap import mmap, ACCESS_READ
 
-import numpy as np
+import numpy as np  # noqa
 from ..py3k import asbytes, asstr
 from numpy import fromstring, ndarray, dtype, empty, array, asarray
 from numpy import little_endian as LITTLE_ENDIAN
 from functools import reduce
 
-from .six import integer_types
+from six import integer_types
 
 
 ABSENT = b'\x00\x00\x00\x00\x00\x00\x00\x00'