从dataframe单元格读取类似值的列表

Question

我从facebook api fbRads中提取了数据。以下是我所拥有的数据框架示例：

mydata <-  fread('ID,ACTIONS
      02,"list(action_type = c("link_click", "post_reaction", "page_engagement", "post_engagement"), value = c("1", "4", "5", "5"))"
      03,"list(action_type = c("app_custom_event.fb_mobile_activate_app", "app_custom_event.fb_mobile_add_to_cart", "app_custom_event.fb_mobile_content_view", "app_custom_event.fb_mobile_purchase", "app_custom_event.fb_mobile_search", "app_custom_event.other", "like", "link_click", "mobile_app_install", "offsite_conversion.fb_pixel_add_to_cart", "offsite_conversion.fb_pixel_add_to_wishlist", "offsite_conversion.fb_pixel_lead", "offsite_conversion.fb_pixel_purchase", "offsite_conversion.fb_pixel_search", "offsite_conversion.fb_pixel_view_content", "post_reaction", "page_engagement", "post_engagement", "offsite_conversion", "app_custom_event"), value = c("994", "219", "1696", "9", "47", "425", "67", "2267", "37", "348", "53", "3", "7", "218", "3286", "145", "2479", "2412", "3915", "3390"))"
      04,"NULL"
      05,"list(action_type = c("app_custom_event.fb_mobile_activate_app", "app_custom_event.fb_mobile_add_to_cart", "app_custom_event.fb_mobile_content_view", "app_custom_event.fb_mobile_purchase", "app_custom_event.fb_mobile_search", "app_custom_event.other", "like", "link_click", "mobile_app_install", "offsite_conversion.fb_pixel_add_to_cart", "offsite_conversion.fb_pixel_add_to_wishlist", "offsite_conversion.fb_pixel_lead", "offsite_conversion.fb_pixel_purchase", "offsite_conversion.fb_pixel_search", "offsite_conversion.fb_pixel_view_content", "post", "post_reaction", "page_engagement", "post_engagement", "offsite_conversion", "app_custom_event"), value = c("1703", "188", "2233", "13", "155", "731", "229", "2568", "62", "303", "46", "7", "17", "257", "4433", "1", "473", "3271", "3042", "5063", "5023"))"')

我需要查找针对每个id的app_custom_event.fb_mobile_purchase值。操作列在每个单元格中包含两个列表，即action_type和value。

我期望的产出是：

mydata <-  fread('ID,app_custom_event.fb_mobile_purchase
      02,"NULL"
      03,"9"
      04,"NULL"
      05,"13"')

我需要使用字典来获取值吗？任何方法都将受到高度赞赏。

Answer 1

以下是一个开始：

lapply(mydata$ACTIONS, function(i){
  x <- eval(parse(text = i))
  ix <- which(x$action_type == "app_custom_event.fb_mobile_purchase")
  x$value[ ix ]
})

我不知道fbRads包，但它必须有一些“读取”功能，以避免这个问题。