From e926338b69c08605587a0993ff5242be521ab580 Mon Sep 17 00:00:00 2001
From: Pim Nelissen <pim.nelissen@protonmail.com>
Date: Wed, 25 Feb 2026 14:17:14 +0100
Subject: [PATCH] add InvalidIsotopeError and DimensionError

---
 src/pg_rad/exceptions/exceptions.py | 14 +++++++++++---
 src/pg_rad/isotopes/isotope.py      |  3 ++-
 src/pg_rad/objects/objects.py       |  4 +++-
 3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/src/pg_rad/exceptions/exceptions.py b/src/pg_rad/exceptions/exceptions.py
index 37355aa..0b5a474 100644
--- a/src/pg_rad/exceptions/exceptions.py
+++ b/src/pg_rad/exceptions/exceptions.py
@@ -14,12 +14,20 @@ class OutOfBoundsError(Exception):
     """Raised when an object is attempted to be placed out of bounds."""
 
 
-class MissingNestedKeyError(Exception):
-    """Raised when a nested key is missing in the config."""
+class MissingConfigKeyError(KeyError):
+    """Raised when a (nested) config key is missing in the config."""
     def __init__(self, key, subkey=None):
         if subkey:
-            self.message = f"Missing key in {key}: {subkey}"
+            self.message = f"Missing key in {key}: {', '.join(list(subkey))}"
         else:
             self.message = f"Missing key: {key}"
 
         super().__init__(self.message)
+
+
+class DimensionError(ValueError):
+    """Raised if dimensions or coordinates do not match the system."""
+
+
+class InvalidIsotopeError(ValueError):
+    """Raised if attempting to load an isotope that is not valid."""
diff --git a/src/pg_rad/isotopes/isotope.py b/src/pg_rad/isotopes/isotope.py
index 218b36f..9e7aa77 100644
--- a/src/pg_rad/isotopes/isotope.py
+++ b/src/pg_rad/isotopes/isotope.py
@@ -1,5 +1,6 @@
 from typing import Dict, Type
 
+from pg_rad.exceptions.exceptions import InvalidIsotopeError
 from pg_rad.physics.attenuation import get_mass_attenuation_coeff
 
 
@@ -46,5 +47,5 @@ preset_isotopes: Dict[str, Type[Isotope]] = {
 def get_isotope(isotope_str: str) -> Isotope:
     """Lazy factory function to create isotope objects."""
     if isotope_str not in preset_isotopes:
-        raise ValueError(f"Unknown isotope: {isotope_str}")
+        raise InvalidIsotopeError(f"Unknown isotope: {isotope_str}")
     return preset_isotopes[isotope_str]()
diff --git a/src/pg_rad/objects/objects.py b/src/pg_rad/objects/objects.py
index d3ec285..ab036cd 100644
--- a/src/pg_rad/objects/objects.py
+++ b/src/pg_rad/objects/objects.py
@@ -2,6 +2,8 @@ from typing import Self
 
 import numpy as np
 
+from pg_rad.exceptions.exceptions import DimensionError
+
 
 class BaseObject:
     def __init__(
@@ -21,7 +23,7 @@ class BaseObject:
         """
 
         if len(pos) != 3:
-            raise ValueError("Position must be tuple of length 3 (x,y,z).")
+            raise DimensionError("Position must be tuple of length 3 (x,y,z).")
         self.pos = pos
         self.name = name
         self.color = color