feat: add get_child_fields to list child fields UIDs, bump version and changelog

Author: Simlomb

CHANGELOG.md

@@ -14,6 +14,7 @@ and **Merged pull requests**. Critical items to know are:
 Referenced versions in headers are tagged on Github, in parentheses are for pypi.
 
 ## [vxx](https://github.com/pydicom/deid/tree/master) (master)
+- Fix field removal and blanking to clean up child UID references [#293](https://github.com/pydicom/deid/pull/293) (0.4.9)
 - Fix UID lookup for nested sequence fields in DICOM datasets [#292](https://github.com/pydicom/deid/pull/292) (0.4.8)
 - Allow saving with a compressed transfer syntax [#290](https://github.com/pydicom/deid/pull/290) (0.4.7)
 - Improve performance of header deid with caching and lookup tables [#289](https://github.com/pydicom/deid/pull/289)

deid/dicom/parser.py

@@ -176,6 +176,17 @@ def get_nested_field(self, field, return_parent=False):
             return parent, desired
         return desired
 
+    def get_child_fields(self, field):
+        """
+        Return a list of child field UIDs for a given field.
+
+        This method identifies all field UIDs in self.fields that are nested under the provided field,
+        based on the UID prefix convention (parent UID + '__').
+        It is used to find and remove all child fields when blanking or deleting a parent field (e.g., a sequence).
+        """
+        field_uid_prefix = field.uid + "__"
+        return [uid for uid in self.fields if uid.startswith(field_uid_prefix)]
+
     def delete_field(self, field):
         """
         Delete a field from the dicom.
@@ -191,11 +202,7 @@ def delete_field(self, field):
             # Remove the field itself from the lookup
             self.fields.remove(field.uid)
             # Also remove any child fields that were nested under this field
-            field_uid_prefix = field.uid + "__"
-            child_uids = [
-                uid for uid in self.fields if uid.startswith(field_uid_prefix)
-            ]
-            for child_uid in child_uids:
+            for child_uid in self.get_child_fields(field):
                 self.fields.remove(child_uid)
 
     def blank_field(self, field):
@@ -211,11 +218,7 @@ def blank_field(self, field):
         if parent and desired in parent:
             parent[desired].value = None
             # Also remove any child fields that were nested under this field
-            field_uid_prefix = field.uid + "__"
-            child_uids = [
-                uid for uid in self.fields if uid.startswith(field_uid_prefix)
-            ]
-            for child_uid in child_uids:
+            for child_uid in self.get_child_fields(field):
                 self.fields.remove(child_uid)
 
     def replace_field(self, field, value):

deid/version.py

@@ -2,7 +2,7 @@
 __copyright__ = "Copyright 2016-2025, Vanessa Sochat"
 __license__ = "MIT"
 
-__version__ = "0.4.8"
+__version__ = "0.4.9"
 AUTHOR = "Vanessa Sochat"
 AUTHOR_EMAIL = "[email protected]"
 NAME = "deid"