ENH: allow to override a subject id if a single sequence dicoms provided

Author: DBIC BIDS Team

bin/heudiconv

@@ -1533,7 +1533,6 @@ def get_study_sessions(dicom_dir_template, files_opt, heuristic, outdir,
     else:
         # prep files
         assert files_opt
-        assert not sids
         files = []
         for f in files_opt:
             if isdir(f):
@@ -1559,6 +1558,17 @@ def get_study_sessions(dicom_dir_template, files_opt, heuristic, outdir,
             raise NotImplementedError(
                 "For now, if no subj template is provided, requiring "
                 "heuristic to have infotoids")
+        
+        if sids:
+            if not (len(sids) == 1 and len(seqinfo_dict) == 1):
+                raise RuntimeError(
+                    "We were provided some subjects (%s) but we can deal only "
+                    "with overriding only 1 subject id. Got %d subjects and "
+                    "found %d sequences" % (sids, len(sids), len(seqinfo_dict))
+                )
+            sid = sids[0]
+        else:
+            sid = None
 
         for studyUID, seqinfo in seqinfo_dict.items():
             # so we have a single study, we need to figure out its
@@ -1575,7 +1585,8 @@ def get_study_sessions(dicom_dir_template, files_opt, heuristic, outdir,
             study_session_info = StudySessionInfo(
                 ids.get('locator'),
                 ids.get('session', session) or session,
-                ids.get('subject', None))
+                sid or ids.get('subject', None)
+            )
             if study_session_info in study_sessions:
                 #raise ValueError(
                 lgr.warning(