import math, operator

def main():
	print '\nHello and welcome to my calculator!'

	operators = {
		'+': operator.add,
		'-': operator.sub,
		'*': operator.mul,
		'/': operator.truediv,
		'sine': math.sin
	}

	while 1:
		function = raw_input('\nPlease input the function you would' +
			'like to use. These include +, -, *, /, sine.\n')

		try:
			op = operators[function]
		except:
			print 'Sorry, that is an incorrect function.'
			continue

		if op != math.sin:
			print '\nNow please input the two variables.'
			firstnum = float(raw_input())
			secondnum = float(raw_input())
			answer = op(firstnum, secondnum)
		else:
			print '\nPlease enter the angle.'
			angle = float(raw_input())
			answer = math.sin(angle)

		print 'Your answer is %f ' % answer
		print '\nWhen you are ready to quit, simply press Ctrl + C'

main()