Evaluation of Postfix Expression

postfix_eval.py

import sys
test_cases = open(sys.argv[1], 'r')

def eval_postfix(exp):
	stack = []
	for i in exp:
		try:
			val = int(i)
			stack.append(val)
		except:
			val1 = stack.pop()
			val2 = stack.pop()
			if i == '+':
				val = val1 + val2
			elif i == '*':
				val = val1 * val2
			elif i == '/':
				val = val1 / val2
			stack.append(val)
	return stack[-1]

for test in test_cases:
	strs = test.replace('\n', '')
	els = strs.split(' ')
	print eval_postfix(els[::-1])

test_cases.close()