Converts NeuroML arithmetic/logical operators to python equivalents.

        @param op: NeuroML operator
        @type op: string


        @return: Python operator
        @rtype: string

def convert_op(self, op):
        """
        Converts NeuroML arithmetic/logical operators to python equivalents.

        @param op: NeuroML operator
        @type op: string


        @return: Python operator
        @rtype: string
        """

        if op == '.gt.':
            return '>'
        elif op == '.ge.' or op == '.geq.':
            return '>='
        elif op == '.lt.':
            return '<'
        elif op == '.le.':
            return '<='
        elif op == '.eq.':
            return '=='
        elif op == '.neq.':   
            return '!='
        elif op == '.ne.':   # .neq. is preferred!
            return '!='
        elif op == '^':
            return '**'
        elif op == '.and.':
            return 'and'
        elif op == '.or.':
            return 'or'
        else:
            return op