Minor improvements for porting to Python 3

Author: digaru19

odml/__init__.py

@@ -1,11 +1,16 @@
-_property = property
 import sys
 from odml import doc
 from odml import property
 from odml import section
 from odml import value
 from odml.dtypes import DType
 
+# the original property-function is overwritten
+# so get it back!
+try:
+    from builtins import property as _property
+except ImportError:
+    from __builtin__ import property as _property
 
 class odml_implementation(object):
     name = None

odml/base.py

@@ -54,6 +54,12 @@ def __ne__(self, obj):
         """
         return not self == obj
 
+    def __hash__(self):
+        '''
+            Define a default hash function for all odML objects
+        '''
+        return id(self)
+
     def clean(self):
         """
         stub that doesn't do anything for this class

odml/dtypes.py

@@ -291,12 +291,12 @@ def calculate_crc32_checksum(data):
 }
 
 # allow to use any available algorithm
-if sys.version_info > (3, 0):
-    for algo in hashlib.algorithms_guaranteed:
-        checksums[algo] = lambda data, func=getattr(hashlib, algo): func(data).hexdigest()
-elif not sys.version_info < (2, 7):
-    for algo in hashlib.algorithms:
-        checksums[algo] = lambda data, func=getattr(hashlib, algo): func(data).hexdigest()
+try:
+    hash_algorithms = hashlib.algoritms
+except AttributeError:
+    hash_algorithms = hashlib.algorithms_guaranteed
+for algo in hash_algorithms:
+    checksums[algo] = lambda data, func=getattr(hashlib, algo): func(data).hexdigest()
 
 
 def valid_checksum_type(checksum_type):

odml/format.py

@@ -18,7 +18,7 @@ def revmap(self, name):
         if self._rev_map is None:
             # create the reverse map only if requested
             self._rev_map = {}
-            for k, v in self._map.iteritems():
+            for k, v in self._map.items():
                 self._rev_map[v] = k
         return self._rev_map.get(name, name)
 

odml/terminology.py

@@ -9,11 +9,12 @@
 import odml.tools.xmlparser
 from hashlib import md5
 py3 = True
+
 try:
-    import urllib.request as urllib2
+    from urllib.request import urlopen
 except ImportError:
-    import urllib2
-    py3 = False
+    from urllib import urlopen
+
 import threading
 
 CACHE_AGE = datetime.timedelta(days=1)
@@ -24,7 +25,7 @@ def cache_load(url):
     load the url and store it in a temporary cache directory
     subsequent requests for this url will use the cached version
     """
-    filename = '.'.join([md5(url.encode()).hexdigest(), os.path.basename(url)])
+    filename = md5(url.encode()).hexdigest() + os.path.basename(url)
     cache_dir = os.path.join(tempfile.gettempdir(), "odml.cache")
     if not os.path.exists(cache_dir):
         try:
@@ -37,16 +38,15 @@ def cache_load(url):
        or datetime.datetime.fromtimestamp(os.path.getmtime(cache_file)) < \
        datetime.datetime.now() - CACHE_AGE:
         try:
-            data = urllib2.urlopen(url).read().decode("latin1")
+            data = urlopen(url).read().decode("utf-8")
         except Exception as e:
-            print("failed loading '%s': %s" % (url, e))
+            print("Failed loading '%s': %s" % (url, e))
             return
+
         fp = open(cache_file, "w")
-        if py3:
-            fp.write(data)
-        else:
-            fp.write(data.encode('latin1'))
+        fp.write(data)
         fp.close()
+
     return open(cache_file)
 
 
@@ -74,7 +74,7 @@ def _load(self, url):
         # if url.startswith("http"): return None
         fp = cache_load(url)
         if fp is None:
-            print("did not successfully load '%s'" % url)
+            print("Did not successfully load '%s'" % url)
             return
         try:
             term = odml.tools.xmlparser.XMLReader(filename=url, ignore_errors=True).fromFile(fp)

odml/tools/nodes.py

@@ -78,6 +78,8 @@ def next(self):
         except IndexError:
             return None
 
+    __next__ = next
+
     @property
     def position(self):
         return self.parent.path_to(self)[-1]

odml/validation.py

@@ -124,7 +124,7 @@ def section_repository_should_be_present(sec):
     try:
         tsec = sec.get_terminology_equivalent()
     except Exception as e:
-        yield ValidationError(sec, 'Could not load terminology: ' + e.message, 'warning')
+        yield ValidationError(sec, 'Could not load terminology: ' + e, 'warning')
         return
 
     if tsec is None: