RF+BF - make dicom and PIL.Image optional

We were depending on these packages to run the tests.

Author: matthew-brett

nibabel/dft.py

@@ -9,13 +9,18 @@
 # Copyright (C) 2011 Christian Haselgrove
 
 import os
-import struct
 import tempfile
 import StringIO
-import numpy
-import nibabel
 import sqlite3
-import dicom
+
+import numpy
+
+from .nifti1 import Nifti1Header
+
+# Shield optional dicom import
+from .optpkg import optional_package
+dicom, have_dicom, _ = optional_package('dicom')
+
 
 class DFTError(Exception):
     "base class for DFT exceptions"
@@ -176,7 +181,7 @@ def as_nifti(self):
 
         m = numpy.array(m)
 
-        hdr = nibabel.nifti1.Nifti1Header(endianness='<')
+        hdr = Nifti1Header(endianness='<')
         hdr.set_intent(0)
         hdr.set_qform(m, 1)
         hdr.set_xyzt_units(2, 8)

nibabel/tests/test_dft.py

@@ -3,17 +3,28 @@
 
 from os.path import join as pjoin, dirname
 import StringIO
-import PIL.Image
-from nose.tools import assert_true, assert_false, assert_equal, assert_raises
+
+import numpy as np
+
 from .. import dft
 from .. import nifti1
 
+from nose.tools import (assert_true, assert_false, assert_equal, assert_raises)
+
+# Shield optional package imports
+from ..optpkg import optional_package
+# setup_module will raise SkipTest if no dicom to import
+dicom, have_dicom, setup_module = optional_package('dicom')
+PImage, have_pil, _ = optional_package('PIL.Image')
+pil_test = np.testing.dec.skipif(not have_pil, 'could not import PIL.Image')
+
 data_dir = pjoin(dirname(__file__), 'data')
 
+
 def test_init():
     dft.clear_cache()
     dft.update_cache(data_dir)
-    return
+
 
 def test_study():
     studies = dft.get_studies(data_dir)
@@ -42,32 +53,35 @@ def test_series():
     assert_equal(ser.bits_allocated, 16)
     assert_equal(ser.bits_stored, 12)
 
+
 def test_storage_instances():
     studies = dft.get_studies(data_dir)
     sis = studies[0].series[0].storage_instances
     assert_equal(len(sis), 2)
     assert_equal(sis[0].instance_number, 1)
     assert_equal(sis[1].instance_number, 2)
-    assert_equal(sis[0].uid, 
+    assert_equal(sis[0].uid,
                  '1.3.12.2.1107.5.2.32.35119.2010011420300180088599504.0')
-    assert_equal(sis[1].uid, 
+    assert_equal(sis[1].uid,
                  '1.3.12.2.1107.5.2.32.35119.2010011420300180088599504.1')
 
+
 def test_storage_instance():
-    return
+    pass
 
+
+@pil_test
 def test_png():
     studies = dft.get_studies(data_dir)
     data = studies[0].series[0].as_png()
-    im = PIL.Image.open(StringIO.StringIO(data))
+    im = PImage.open(StringIO.StringIO(data))
     assert_equal(im.size, (256, 256))
-    return
+
 
 def test_nifti():
     studies = dft.get_studies(data_dir)
     data = studies[0].series[0].as_nifti()
     assert_equal(len(data), 352 + 2*256*256*2)
     h = nifti1.Nifti1Header(data[:348])
     assert_equal(h.get_data_shape(), (256, 256, 2))
-    return