Better error message

Summary

This very small MR just adds two more verbose error messages for two mistakes that can appear during cfood development.

Please see the in-code comments for details.

Test Environment

There are unit tests.

Check List for the Author

Please, prepare your MR for a review. Be sure to write a summary and a focus and create gitlab comments for the reviewer. They should guide the reviewer through the changes, explain your changes and also point out open questions. For further good practices have a look at our review guidelines

• All automated tests pass
• Reference related issues
• Up-to-date CHANGELOG.md (or not necessary)
• Up-to-date JSON schema (or not necessary)
• Appropriate user and developer documentation (or not necessary)
  • How do I use the software? Assume "stupid" users.
  • How do I develop or debug the software? Assume novice developers.
• 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 (or not necessary)
• Appropriate user and developer documentation (or not necessary)
• 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 specifications? Are they satisfied?

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

src/caoscrawler/identifiable.py

@@ -80,7 +80,7 @@ class Identifiable():
     def get_representation(self) -> str:
         return sha256(Identifiable._create_hashable_string(self).encode('utf-8')).hexdigest()
 
-    @ staticmethod
+    @staticmethod
     def _value_representation(value) -> str:
         """returns the string representation of property values to be used in the hash function
 
@@ -103,7 +103,7 @@ class Identifiable():
         else:
             raise ValueError(f"Unknown datatype of the value: {value}")
 
-    @ staticmethod
+    @staticmethod
     def _create_hashable_string(identifiable: Identifiable) -> str:
         """
         creates a string from the attributes of an identifiable that can be hashed