Add an anomaly message type for collecting interesting or unusual artefacts about a disk structure.

src/apple2disk/anomaly.py

@@ -0,0 +1,29 @@
+import sys
+
+class AnomalyLevel(object):
+    def __init__(self, level):
+        self.level = level
+
+    def __str__(self):
+        return level
+
+module = sys.modules[__name__]
+for level in ['INFO', 'UNUSUAL', 'CORRUPTION']:
+    setattr(module, level, AnomalyLevel(level))
+
+
+class Anomaly(object):
+    def __init__(self, container, level, details):
+        """Record of an anomaly found during disk processing.
+        
+        Args:
+            container: object that contains the anomaly
+            level: AnomalyLevel
+            details: string description of anomaly (str)
+        """
+        self.container = container
+        self.level = level
+        self.details = details
+
+    def __str__(self):
+        return '%s anomaly in %s: %s' % (self.level, self.container, self.details)