Apple Music批量导出播放列表脚本报错：变量all_ps未定义

错误的核心是变量类型不匹配：你把all_ps初始定义成了字符串"{}"，但后续代码用set the end of all_ps是给列表添加元素的语法，字符串不支持这种操作，导致变量操作失败，系统判定all_ps未正确定义。

修复步骤 #

把set all_ps to "{}"这一行改成：

set all_ps to {}

这会把all_ps初始化为一个空列表，后续的set the end of all_ps操作就能正常给列表添加元素了。

修正后的完整代码片段 #

try
    set all_specialps to (get name of every user playlist whose special kind is not none)
    set all_userps to (get name of every user playlist whose smart is false and special kind is none)
    set all_smartps to (get name of every user playlist whose smart is true and special kind is none)
    
    set delim to "--------------------------------------------------"
    set delim_specialpl to "---------------- Special Playlists: ----------------"
    set delim_userpl to "------------------ User Playlists: -----------------"
    set delim_smartpl to "---------------- Smart Playlists: -----------------"
    set all_ps to {} -- 这里改成空列表，不是字符串
    if ((length of all_specialps) > 0) then
        set the end of all_ps to delim
        set the end of all_ps to delim_specialpl
        repeat with ps in all_specialps
            set the end of all_ps to ps
        end repeat
    end if
    if ((length of all_userps) > 0) then
        set the end of all_ps to delim
        set the end of all_ps to delim_userpl
        repeat with ps in all_userps
            set the end of all_ps to ps
        end repeat
    end if
    if ((length of all_smartps) > 0) then
        set the end of all_ps to delim
        set the end of all_ps to delim_smartpl
        repeat with ps in all_smartps
            set the end of all_ps to ps
        end repeat
    end if
end try

额外说明 #

• AppleScript里，{}表示空列表，"{}"是包含这两个字符的字符串，两者完全不同
• 后续的set the end of ...只能对列表类型的变量使用，字符串没有“末尾添加元素”的概念

内容的提问来源于stack exchange，提问作者KirklandStackOF