def _top(self, n=0):
        """Read a value from the top of the stack without removing it"""
        if len(self.stack) - n < 0:
            raise StackUnderflow()
        return self.stack[n - 1]
def _top(self, n=0):
        
        if len(self.stack) - n < 0:
            raise StackUnderflow()
        return self.stack[n - 1]
def _top ( self , n = 0 ) : if len ( self . stack ) - n < 0 : raise StackUnderflow ( ) return self . stack [ n - 1 ]
Read a value from the top of the stack without removing it
Read a value from the top of the stack without removing it