add InvalidIsotopeError and DimensionError

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):
+class MissingConfigKeyError(KeyError):
-    """Raised when a nested key is missing in the config."""
+    """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."""

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]()

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