Fix lookup of element tag given attribute keyword

Author: hackermd

src/dicomweb_client/__init__.py

@@ -1,3 +1,3 @@
-__version__ = '0.9.3'
+__version__ = '0.9.4'
 
 from dicomweb_client.api import DICOMwebClient

src/dicomweb_client/api.py

@@ -15,7 +15,7 @@
 import requests
 import pydicom
 
-from dicomweb_client.error import DICOMJSONError
+from dicomweb_client.error import DICOMJSONError, HTTPError
 
 
 logger = logging.getLogger(__name__)
@@ -152,7 +152,7 @@ def load_json_dataset(dataset):
         try:
             value = mapping['Value']
         except KeyError:
-            logger.warn(
+            logger.debug(
                 'mapping for data element "{}" has no "Value" key'.format(tag)
             )
             value = [None]
@@ -412,7 +412,12 @@ def _http_get(self, url, params, headers):
         url += self._build_query_string(params)
         logger.debug('GET: {}'.format(url))
         response = self._session.get(url=url, headers=headers)
-        response.raise_for_status()
+        try:
+            response.raise_for_status()
+        except requests.exceptions.HTTPError as error:
+            raise HTTPError(error)
+        if response.status_code == 204:
+            logger.warn('empty response')
         # The server may not return all results, but rather include a warning
         # header to notify that client that there are remaining results.
         # (see DICOM Part 3.18 Section 6.7.1.2)
@@ -1147,4 +1152,4 @@ def lookup_tag(keyword):
         '''
         tag = pydicom.datadict.tag_for_keyword(keyword)
         tag = pydicom.tag.Tag(tag)
-        return '{0:04x}{1:04x}'.format(tag.group, tag.element)
+        return '{0:04x}{1:04x}'.format(tag.group, tag.element).upper()

src/dicomweb_client/error.py

@@ -1,6 +1,12 @@
 '''Custom error classes'''
+import requests
 
 
 class DICOMJSONError(ValueError):
     '''Exception class for malformatted DICOM JSON.'''
     pass
+
+
+class HTTPError(requests.exceptions.HTTPError):
+    '''Exception class for HTTP requests with failure status codes.'''
+    pass

src/dicomweb_client/tests/test_api.py

@@ -6,6 +6,20 @@
 import pydicom
 
 
+def test_lookup_tag(httpserver, client):
+    assert client.lookup_tag('StudyInstanceUID') == '0020000D'
+    assert client.lookup_tag('SeriesInstanceUID') == '0020000E'
+    assert client.lookup_tag('SOPInstanceUID') == '00080018'
+    assert client.lookup_tag('PixelData') == '7FE00010'
+
+
+def test_lookup_keyword(httpserver, client):
+    assert client.lookup_keyword('0020000D') == 'StudyInstanceUID'
+    assert client.lookup_keyword('0020000E') == 'SeriesInstanceUID'
+    assert client.lookup_keyword('00080018') == 'SOPInstanceUID'
+    assert client.lookup_keyword('7FE00010') == 'PixelData'
+
+
 def test_search_for_studies(httpserver, client, cache_dir):
     cache_filename = os.path.join(cache_dir, 'search_for_studies.json')
     with open(cache_filename, 'r') as f: