can follow user steps up until fraction reduction

expressionTree.py

-# Equation Tree class
-# AI Final Project
-# Takes an equation of the form x + 3 = 5 + x and makes this into an equation tree
-# this means = is in root and each expression is a tree on either side
-# currently only works for addition and two variables on each side of equation
-
-class EquationTreeNode:
-	def __init__(self, value, parent=None):
-		self.value = value
-		self.left = None
-		self.right = None
-		self.parent = parent
-
-	def setLeft(self, newNode):
-		self.left = newNode
-
-	def setRight(self, newNode):
-		self.right = newNode
-
-	def addLeftNode(self, newNode):
-		self.left = newNode
-		newNode.parent = self
-
-	def addRightNode(self, newNode):
-		self.right = newNode
-		newNode.parent = self
-
-	def splitExpression(self, expression):
-		expressions = expression.split("+")
-		leftNode = EquationTreeNode(expressions[0])
-		rightNode = EquationTreeNode(expressions[1])
-		self.addLeftNode(leftNode)
-		self.addRightNode(rightNode)
-
-'''def main():
-	equation = "3x+5=2+2x"
-	expressions = equation.split("=")
-	rootNode = EquationTreeNode("=", None)
-	
-	leftNode = EquationTreeNode("+")
-	rootNode.addLeftNode(leftNode)
-	splitExpression(expressions[0], leftNode)
-	
-	rightNode = EquationTreeNode("+")
-	rootNode.addRightNode(rightNode)
-	splitExpression(expressions[1], rightNode)
-
-
-	print(rootNode.value)
-	print(rootNode.left.value, rootNode.right.value)
-	print(rootNode.left.left.value, rootNode.left.right.value, rootNode.right.left.value, rootNode.right.right.value)
-
-
-main()	'''
\ No newline at end of file

tree.py

@@ -28,12 +28,17 @@ class EquationTree:
             self.inorder(node.right)
 
     def evaluate(self, parent, left):
+        # can simplify this to call helper function
         if left:
             if parent.left.canEval():
+                print("parent.left.left is ", parent.left.left.value)
+                print("parent.left.right is ", parent.left.right)
                 if isinstance(parent.left.left, NumNode):
+                    print("num node")
                     print("evaluating", parent.left.eval())
                     newNode = NumNode(parent.left.eval())
                 else:
+                    print("variable node")
                     print("evaluating", parent.left.eval())
                     newNode = VariableNode(str(parent.left.eval()) + "x")
                 parent.left = newNode
@@ -113,14 +118,20 @@ class PlusNode:
         self.value = "+"
         
     def canEval(self):
-        if isinstance(self.left, VariableNode) == isinstance(self.right,VariableNode):
+        if isinstance(self.left, VariableNode) and isinstance(self.right,VariableNode):
             return True
-        return False
+        elif isinstance(self.left, NumNode) and isinstance(self.right, NumNode):
+            return True
+        else:
+            return False
 
     def getInverse(self):
         return MinusNode(None,None)
 
     def eval(self):
+        #print("left value ", self.left)
+        #print(isinstance(self.left, NumNode))
+        #print("right value ", self.right.value())
         return self.left.eval() + self.right.eval()
     
     
@@ -134,9 +145,12 @@ class MinusNode:
         self.value = "-"
 
     def canEval(self):
-        if isinstance(self.left, VariableNode) == isinstance(self.right,VariableNode):
+        if isinstance(self.left, VariableNode) and isinstance(self.right,VariableNode):
+            return True
+        elif isinstance(self.left, NumNode) and isinstance(self.right, NumNode):
             return True
-        return False
+        else:
+            return False
 
     def getInverse(self):
         return PlusNode(None, None)
@@ -353,6 +367,12 @@ def main():
     equationTree.printTree()
     equationTree.get_expression()
         
+
+'''
+print("old node should be 2, is ", oldNum.value)
+                print("moved node should be 7, is ", moveNode.value)
+                print("new op is ", newOp.value)
+                '''
     
 if __name__ == "__main__":
     main()
\ No newline at end of file