A prototype/doodle for a equation generation algorithm.

ega.py

# Equation Generation Algorithm - prototype script.
import random;

class EquationType:
	def __init__(self,pycode,argcount):
		self.pycode = pycode;
		self.argcount = argcount;
		
arith = lambda: None
arith.ADD = EquationType("+",2);
arith.SUB = EquationType("-",2);
arith.MUL = EquationType("*",2);
arith.DIV = EquationType("/",2);
arith.POW = EquationType("**",2);

		
class Equation(object):	
	result = None;
	
	def __init__(self,type,left="",right=""):
		self.type = type;	#Equation type
		self.left = left;
		self.right = right;
	
	def eval(self):
		lt = self.left.eval() if type(self.left) == type(self) else self.left;
		rt = self.right.eval() if type(self.right) == type(self) else self.right;
		self.result = eval(str(lt) + str(self.type.pycode) + str(rt))
		return self.result;
		
	def __str__(self):
		return "(" + str(self.left) + str(self.type.pycode) + str(self.right) + ")";
	
	@staticmethod
	def generate(factorcount,rangeFactors):
		assert factorcount >= 2
		# generate factors
		factors = [];
		for k in range(factorcount):
			factors.append(random.randint(rangeFactors[0],rangeFactors[1]));
		# compose equation
		eq = factors.pop();
		for k in factors:
			operator = random.choice([arith.ADD,arith.SUB,arith.MUL]);
			eq = Equation(operator,eq,k) if random.choice([True,False]) else Equation(operator,k,eq);
		return eq;

# Test
eq = Equation.generate(3,(0,10));
print (str(eq) + " = " + str(eq.eval()));