Checkpoint initial implementation

tungston/core/scarcity.py

@@ -0,0 +1,27 @@
+# Class ############################################################################################
+
+class Scarcity:
+    """
+    How frequently something appears within a given region.
+    """
+
+    def __init__(self, name):
+        self.name = name
+
+    def __str__(self) -> str:
+        return self.name
+
+    def __repr__(self) -> str:
+        return f"Scarcity<{self.name}>"
+
+# Constants ########################################################################################
+
+ABSENT   = Scarcity("absent")
+RARE     = Scarcity("rare")
+UNUSUAL  = Scarcity("unusual")
+SPARSE   = Scarcity("sparse")
+UNCOMMON = Scarcity("uncommon")
+COMMON   = Scarcity("common")
+CARPET   = Scarcity("carpet")
+
+ALL = [ABSENT, RARE, UNUSUAL, SPARSE, UNCOMMON, COMMON, CARPET]