[m0dem]

Well, I've had this lying around for awhile, but I was too lazy to post until now.

Code:

from __future__ import print_function def tokenize(code): return code.split() def evaluate(code, stack, operators): tokens = tokenize(code) for token in tokens: if token in operators: if token in ["+", "-", "*", "/"]: while len(stack) < 2: stack.append(0) ret = operators[token](stack) if ret != None: stack.append(ret) else: # push stack.append(int(token)) stack = [] operators = { "+": lambda stack: stack.pop() + stack.pop(), "-": lambda stack: stack.pop() - stack.pop(), "*": lambda stack: stack.pop() * stack.pop(), "/": lambda stack: stack.pop() / stack.pop(), "|": lambda stack: print(stack[-1]), "=": lambda stack: int(stack.pop() == stack.pop()), "!": lambda stack: int(stack.pop() != stack.pop()), ">": lambda stack: int(stack.pop() > stack.pop()), "<": lambda stack: int(stack.pop() < stack.pop()) } print("CTRL-D or CTRL-C to close REPL") while True: try: code = raw_input(">>> ") evaluate(code, stack, operators) except KeyboardInterrupt, EOFError: break print("\nthe stack is: " + repr(stack))