import ast


def make_attr_call(attr1, attr2, args=None):
    """
    flor._attr1_._attr2_(arg)
    """
    if args is None:
        return ast.Call(
            func=ast.Attribute(
                value=ast.Attribute(
                    value=ast.Name('flor', ast.Load()),
                    attr=attr1,
                    ctx=ast.Load()
                ),
                attr=attr2,
                ctx=ast.Load()
            ),
            args=[],                                        # arg is None
            keywords=[]
        )
    else:
        return ast.Call(
            func=ast.Attribute(
                value=ast.Attribute(
                    value=ast.Name('flor', ast.Load()),
                    attr=attr1,
                    ctx=ast.Load()
                ),
                attr=attr2,
                ctx=ast.Load()
            ),
            args=args,                                     # arg is not None
            keywords=[]
        )