use a custom AddressException instead of asserts

There's no reason to have asserts thrown around in the source code like
that. This replaces some of them with an AddressException and a new file
called "exceptions.py" to store the exception definitions.

1 files changed, 8 insertions, 0 deletions

diff --git a/pokemontools/exceptions.py b/pokemontools/exceptions.py
new file mode 100644
index 0000000..674f829
--- /dev/null
+++ b/pokemontools/exceptions.py
@@ -0,0 +1,8 @@
+"""
+Custom exceptions used throughout the project.
+"""
+
+class AddressException(Exception):
+    """
+    There was a problem with an address. Maybe it was out of range or invalid.
+    """