first commit

mason.py

@@ -0,0 +1,65 @@
+class System:
+    def __init__(self):
+        self.nodes = []
+    
+    def create(*args):
+        if len(args) == 0:
+            self.nodes.append(Node(self, self.nextname()))
+    
+    def findtransfer(self, source, sink):
+        def findpaths():
+            
+        virtual = False
+        if not source.issource():
+            raise ValueError('first node must be a source')
+        if not sink.issink():
+            virtual = True
+            self.nodes.append(Node(self, 'virtual'))
+            sink = self.nodes[-1]
+        paths = []
+        loops = []
+        
+    
+    def nextname(self):
+        pass
+    
+    #returns True if there are no connections pointing to the node#returns True if there are no connections pointing to the node
+    def issource(self, node):
+        if not isinstance(node, Node):
+            raise TypeError('argument must be a Node')
+        for i in self.nodes:
+            for j in i.connections:
+                if node is j[1]:
+                    return False
+        return True
+        
+    #returns True if there are no connections starting from the node
+    def issink(self, node):
+        if not isinstance(node, Node):
+            raise TypeError('argument must be a Node')
+        return node.issink()
+
+class Node:
+    def __init__(self, system, name):
+        self.system = system
+        self.name = name
+        self.connections = []
+    
+    def connect(target, transfer):
+        self.connections.append((taget, transfer))
+    
+    #returns True if there are no connections pointing to the node
+    def issource(self):
+        return self.system.issource(self)
+    
+    #returns True if there are no connections starting from the node
+    def issink(self):
+        return self.connections == []
+
+class Connection:
+    def __init__(self, target, gain):
+        
+
+class Loop:
+    def __init__(self):
+        pass