Data system refactor and core redesign for public.

Redesigned data and core systems to be public-capable.

bot/data/conditions.py

@@ -0,0 +1,59 @@
+from .connection import _replace_char
+
+
+class Condition:
+    """
+    ABC representing a selection condition.
+    """
+    __slots__ = ()
+
+    def apply(self, key, values, conditions):
+        raise NotImplementedError
+
+
+class NOT(Condition):
+    __slots__ = ('value',)
+
+    def __init__(self, value):
+        self.value = value
+
+    def apply(self, key, values, conditions):
+        item = self.value
+        if isinstance(item, (list, tuple)):
+            if item:
+                conditions.append("{} NOT IN ({})".format(key, ", ".join([_replace_char] * len(item))))
+                values.extend(item)
+            else:
+                raise ValueError("Cannot check an empty iterable!")
+        else:
+            conditions.append("{}!={}".format(key, _replace_char))
+            values.append(item)
+
+
+class GEQ(Condition):
+    __slots__ = ('value',)
+
+    def __init__(self, value):
+        self.value = value
+
+    def apply(self, key, values, conditions):
+        item = self.value
+        if isinstance(item, (list, tuple)):
+            raise ValueError("Cannot apply GEQ condition to a list!")
+        else:
+            conditions.append("{} >= {}".format(key, _replace_char))
+            values.append(item)
+
+
+class Constant(Condition):
+    __slots__ = ('value',)
+
+    def __init__(self, value):
+        self.value = value
+
+    def apply(self, key, values, conditions):
+        conditions.append("{} {}".format(key, self.value))
+
+
+NULL = Constant('IS NULL')
+NOTNULL = Constant('IS NOT NULL')