Simple Calculator for Python Work group

org.tehlug.Calc.py

def add(x, y):
	return x + y

def sub(x, y):
	return x - y

def mul(x, y):
	return x * y

def div(x, y):
	return x / y

def calculate(x, func, y):

	try:
		return func(x, y)
	except (NameError, TypeError) :
		return 'func name is Wrong!use add, sub, mul and div'
	except ZeroDivisionError:
		return 'Division By Zero Is Not Allowed!!!'
	except Exception:
		return 'Unknown Error!'
while True:
	try:
		x, func , y = input()
	except Exception:
		print 'Please Enter Correct Input! Use flowing format number1,function,number2'
		continue
	print calculate(float(x), func, float(y))

#>>>3,add,2
#5.0
#>>>3,mul,4              
#12.0
#>>>4,div,0
#Division By Zero Is Not Allowed!!!