F retrieve substructure

Summary

This adds a new function in pylib that allows for retrieving connected parts of a data model. This function is needed for feasible conversion of parts of the data model into UML.

This MR also adds some missing docstrings to old functions.

Focus

There is only one function to check that recursively adds substructure starting from a few given entities.

Test Environment

Check out the branch and try this on an instance of your choice:

import caosdb as db
from caosdb.utils.plantuml import to_graphics, retrieve_substructure
rts = retrieve_substructure(db.execute_query("Find RecordType SomeRecordtype"), 2)

Check List for the Author

• All automated tests pass
• Reference related Issues
• Up-to-date CHANGELOG.md
• Annotations in code (Gitlab comments)
  • Intent of new code
  • Problems with old code
  • Why this implementation?

Check List for the Reviewer

• I understand the intent of this MR
• All automated tests pass
• Up-to-date CHANGELOG.md
• The test environment setup works and the intended behavior is reproducible in the test environment
• In-code documentation and comments are up-to-date.
• Check: Are there spezifications? Are they satisfied?

For further good practices have a look at our review guidelines.

src/caosdb/utils/plantuml.py

@@ -223,6 +223,7 @@ package \"The property P references an instance of D\" <<Rectangle>> {
 
     return result
 
+
 def retrieve_substructure(start_record_types, depth, result_id_set=None, result_container=None, cleanup=True):
     """Recursively retrieves CaosDB record types and properties, starting
     from given initial types up to a specific depth.
@@ -262,11 +263,11 @@ def retrieve_substructure(start_record_types, depth, result_id_set=None, result_
             if is_reference(prop.datatype) and prop.datatype != db.FILE and depth > 0:
                 rt = db.RecordType(name=get_referenced_recordtype(prop.datatype)).retrieve()
                 retrieve_substructure([rt], depth-1, result_id_set, result_container, False)
-            else:
-                if prop.id not in result_id_set:
-                    result_container.append(prop)
+
+            if prop.id not in result_id_set:
+                result_container.append(prop)
                 result_id_set.add(prop.id)
-                
+
         for parent in entity.parents:
             rt = db.RecordType(id=parent.id).retrieve()
             if parent.id not in result_id_set:
@@ -278,14 +279,14 @@ def retrieve_substructure(start_record_types, depth, result_id_set=None, result_
     if cleanup:
         return result_container
     return None
-        
-    
+
+
 def to_graphics(recordtypes, filename):
     """Calls recordtypes_to_plantuml_string(), saves result to file and
     creates an svg image
 
     plantuml needs to be installed.
-    
+
     Parameters
     ----------
     recordtypes : Iterable[db.Entity]
@@ -296,7 +297,6 @@ def to_graphics(recordtypes, filename):
     """
     pu = recordtypes_to_plantuml_string(recordtypes)
 
-
     pu_filename = filename+".pu"
     with open(pu_filename, "w") as pu_file:
         pu_file.write(pu)