Remove Python 2 support (#367)

* Removed Python 2 support.

* Updated documentation to indicate removal of Python 2 support.

HISTORY.rst

@@ -4,6 +4,7 @@ History
 
 0.5.7 (unreleased)
 ------------------
+- Dropped support for Python 2.
 
 0.5.6 (2023-05-08)
 ------------------

README.rst

@@ -24,7 +24,6 @@ Dependencies
 -  `numpy <http://www.numpy.org>`__ 1.2 or higher
 -  `pydicom <https://pydicom.github.io>`__ 0.9.9 or higher (pydicom 1.0 compatible)
 -  `matplotlib <http://matplotlib.org>`__ 1.3.0 or higher (for DVH calculation)
--  `six <https://pythonhosted.org/six/>`__ 1.5 or higher
 -  Optional:
 
    -  `Pillow <https://pillow.readthedocs.io>`__ (for image display)

dicompylercore/config.py

@@ -7,52 +7,24 @@
 #    See the file license.txt included with this distribution, also
 #    available at https://github.com/dicompyler/dicompyler-core/
 
-from six import PY2
-
 mpl_available = True
 pil_available = True
 shapely_available = True
 skimage_available = True
 scipy_available = True
 
-if PY2:
-    import imp
-    try:
-        imp.find_module('matplotlib')
-    except ImportError:
-        mpl_available = False
-
-    try:
-        imp.find_module('PIL')
-    except ImportError:
-        pil_available = False
-
-    try:
-        imp.find_module('shapely')
-    except ImportError:
-        shapely_available = False
-
-    try:
-        imp.find_module('skimage')
-    except ImportError:
-        skimage_available = False
+import importlib
 
-    try:
-        imp.find_module('scipy')
-    except ImportError:
-        scipy_available = False
-else:
-    import importlib
-    mpl_available = importlib.util.find_spec("matplotlib") is not None
-    pil_available = importlib.util.find_spec('PIL') is not None
-    shapely_available = importlib.util.find_spec('shapely') is not None
-    skimage_available = importlib.util.find_spec('skimage') is not None
-    scipy_available = importlib.util.find_spec('scipy') is not None
+mpl_available = importlib.util.find_spec("matplotlib") is not None
+pil_available = importlib.util.find_spec("PIL") is not None
+shapely_available = importlib.util.find_spec("shapely") is not None
+skimage_available = importlib.util.find_spec("skimage") is not None
+scipy_available = importlib.util.find_spec("scipy") is not None
 
 
 # DICOM UID prefix
-dicompyler_uid_prefix = '1.2.826.0.1.3680043.8.1070.'
-dicompyler_uid_prefix_image = dicompyler_uid_prefix + '1.'
-dicompyler_uid_prefix_rtstruct = dicompyler_uid_prefix + '2.'
-dicompyler_uid_prefix_rtplan = dicompyler_uid_prefix + '3.'
-dicompyler_uid_prefix_rtdose = dicompyler_uid_prefix + '4.'
+dicompyler_uid_prefix = "1.2.826.0.1.3680043.8.1070."
+dicompyler_uid_prefix_image = dicompyler_uid_prefix + "1."
+dicompyler_uid_prefix_rtstruct = dicompyler_uid_prefix + "2."
+dicompyler_uid_prefix_rtplan = dicompyler_uid_prefix + "3."
+dicompyler_uid_prefix_rtdose = dicompyler_uid_prefix + "4."

dicompylercore/dicomparser.py

@@ -20,8 +20,8 @@
     from dicom.dataset import Dataset
 import random
 from numbers import Number
-from six import PY2, iterkeys, string_types, BytesIO
-from six.moves import range
+from io import BytesIO
+from pathlib import Path
 from dicompylercore import dvh, util
 from dicompylercore.config import pil_available, shapely_available
 
@@ -56,7 +56,7 @@ def __init__(self, dataset, memmap_pixel_array=False):
         self.memmap_pixel_array = memmap_pixel_array
         if isinstance(dataset, Dataset):
             self.ds = dataset
-        elif isinstance(dataset, (string_types, BytesIO)):
+        elif isinstance(dataset, (str, BytesIO, Path)):
             try:
                 with open(dataset, "rb") as fp:
                     self.ds = read_file(fp, defer_size=100, force=True,
@@ -203,8 +203,6 @@ def GetDemographics(self):
                    'birth_date': None,
                    'gender': 'Other'}
         if 'PatientName' in self.ds:
-            if PY2:
-                self.ds.decode()
             name = self.ds.PatientName
             patient['name'] = str(name)
             patient['given_name'] = name.given_name
@@ -668,7 +666,7 @@ def CalculatePlaneThickness(self, planesDict):
         planes = []
 
         # Iterate over each plane in the structure
-        for z in iterkeys(planesDict):
+        for z in planesDict.keys():
             planes.append(float(z))
         planes.sort()
 

dicompylercore/dvhcalc.py

@@ -19,7 +19,6 @@
     from collections.abc import Sequence
 except ImportError:
     from collections import Sequence
-from six import iteritems
 import logging
 logger = logging.getLogger('dicompylercore.dvhcalc')
 
@@ -140,10 +139,10 @@ def _calculate_dvh(structure,
     This is an internal function called by `get_dvh` and
     should not be called directly.
     """
-    planes = collections.OrderedDict(sorted(iteritems(structure['planes'])))
     calcdvh = collections.namedtuple('DVH', ['notes', 'histogram'])
     logger.debug("Calculating DVH of %s %s", structure['id'],
                  structure['name'])
+    planes = collections.OrderedDict(sorted(structure["planes"].items()))
 
     # Create an empty array of bins to store the histogram in cGy
     # only if the structure has contour data or the dose grid exists
@@ -207,7 +206,7 @@ def _calculate_dvh(structure,
             'thickness'] / (interpolation_segments_between_planes + 1)
 
     # Iterate over each plane in the structure
-    for z, plane in iteritems(planes):
+    for z, plane in planes.items():
         # Get the dose plane for the current structure plane
         if interpolation_resolution or use_structure_extents:
             doseplane = get_interpolated_dose(

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py27, py37
+envlist = py37
 
 [testenv]
 setenv =