Fixed a bunch of crap

Nodes/subtract_node.py

@@ -0,0 +1,37 @@
+# Nodes/subtract_node.py
+
+from NodeGraphQt import BaseNode
+
+class SubtractNode(BaseNode):
+    """
+    Subtract Node:
+      - Inputs: A, B
+      - Output: Result (A - B)
+    """
+    __identifier__ = 'io.github.nicole.subtract'
+    NODE_NAME = 'Subtract'
+
+    def __init__(self):
+        super(SubtractNode, self).__init__()
+        self.add_input('A')
+        self.add_input('B')
+        self.add_output('Result')
+        self.value = 0
+
+    def process_input(self):
+        inputs = {}
+        for port_name in ['A', 'B']:
+            port = self.input(port_name)
+            connected = port.connected_ports() if port is not None else []
+            if connected:
+                connected_port = connected[0]
+                parent_node = connected_port.node()
+                try:
+                    inputs[port_name] = float(getattr(parent_node, 'value', 0))
+                except (ValueError, TypeError):
+                    inputs[port_name] = 0.0
+            else:
+                inputs[port_name] = 0.0
+        result = inputs['A'] - inputs['B']
+        self.value = result
+        self.set_name(f"Subtract: {result}")