Instantly share code, notes, and snippets.

Embed
What would you like to do?
"""
Engine class of the RPN Calculator
"""
import math
class rpn_engine:
def __init__(self):
""" Constructor """
self.stack = []
def push(self, number):
""" push a value to the internal stack """
self.stack.append(number)
def pop(self):
""" pop a value from the stack """
try:
return self.stack.pop()
except IndexError:
pass # do not notify any error if the stack is empty...
def sum_two_numbers(self):
op2 = self.stack.pop()
op1 = self.stack.pop()
self.push(op1 + op2)
def subtract_two_numbers(self):
op2 = self.stack.pop()
op1 = self.stack.pop()
self.push(op1 - op2)
def multiply_two_numbers(self):
op2 = self.stack.pop()
op1 = self.stack.pop()
self.push(op1 * op2)
def divide_two_numbers(self):
op2 = self.stack.pop()
op1 = self.stack.pop()
self.push(op1 / op2)
def pow2_a_number(self):
op1 = self.stack.pop()
self.push(op1 * op1)
def sqrt_a_number(self):
op1 = self.stack.pop()
self.push(math.sqrt(op1))
def compute(self, operation):
""" compute an operation """
if operation == '+':
self.sum_two_numbers()
if operation == '-':
self.subtract_two_numbers()
if operation == '*':
self.multiply_two_numbers()
if operation == '/':
self.divide_two_numbers()
if operation == '^2':
self.pow2_a_number()
if operation == 'SQRT':
self.sqrt_a_number()
if operation == 'C':
self.stack.pop()
if operation == 'AC':
self.stack.clear()
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment