postfix.py

import math

#term = input(">> ").split()
stack = []
running = True
while running:
  for t in input(">> ").split():
    if t == "exit":
      running = False
      break
    elif t == "stack":
      pass
    elif t == "clear":
      stack.clear()
    elif t == "pi":
      stack.append(math.pi)
    elif t == "e":
      stack.append(math.e)
    elif t in ["+", "-", "*", "/", "%", "^"]:
      *stack, a, b = stack
      if t == "^":
        t = "**"
      result = eval(str(a) + t + str(b))
      stack.append(result)
    elif t in ["!", "sin", "cos", "tan"]:
      a = stack.pop()
      if t == "!":
        result = math.factorial(a)
      elif t == "sin":
        result = math.sin(a)
      elif t == "cos":
        result = math.cos(a)
      elif t == "tan":
        result = math.tan(a)
      stack.append(result)
    else:
      a = float(t)
      if a.is_integer():
        a = int(a)
      stack.append(a)
    print("Stack:", stack)