def test_evaluate_valid_expressions():
#Testing the positive Test cases
test_io_cases = {
"1 2 3 + -": -4,
"6 2 * 3 /": 4,
"2 3 ^ 4 5 + +": 17,
"50 % 2 *": 1,
"3 ! 4 5 * +": 26,
"12 3 / !": 24,
"5 1 2 + 4 * + 3 -": 14,
}
for expression, expected_output in test_io_cases.iteritems():
actual_op = RPN.evaluate_expression(expression)
print "Output is %s for %s" % (expected_output, expression)
assert actual_op == expected_output
def main():
# Display Help in the beginning of the program.
print RPN.rpn_help()
# Get into a controlled Daemon/infinite loop.
while True:
# Get the RPN expression
input_text = RPN.get_input()
# Check what have you got, if its an expression, call for evaluation
if RPN.is_expression(input_text):
output = RPN.evaluate_expression(input_text)
print output
def test_evaluate_invalid_expressions():
#Testing the Negative Test cases
test_io_cases = {
"2 +": "error : Not enough Operands to proceed with binary operation",
"6sad": "error : Not a Valid RPN, try until you succeed...e.g. 2 3 +",
"2 3 4 +":
"error : Not a Valid RPN, try until you succeed...e.g. 2 3 +",
"-6": "error : Not a Valid RPN, try until you succeed...e.g. 2 3 +",
"!": "error : Not enough Operands to proceed with unary operation",
"%": "error : Not enough Operands to proceed with unary operation"
}
for expression, expected_output in test_io_cases.iteritems():
actual_op = RPN.evaluate_expression(expression)
print "Output is %s for %s" % (expected_output, expression)
assert actual_op == expected_output
