R中的Python zip模式

Question

如何在 R 中对类容器做这样的事情:

class Env(object):
      pass
env = Env()

我想使用(类似 python 的)zip 模式添加实例属性:

medias_name = ("myprint", "ooh", "tv", "digital")
medias_img = ("Print.png", "Ooh.png", "Tv.png", "Digital.png")

for name, value in zip(medias_name, medias_img):
      setattr(env, name, value)

env.digital, env.myprint, env.ooh, env.tv
>>> ('Digital.png', 'Print.png', 'Ooh.png', 'Tv.png')

Answer 1

您可以像这样使用 data.frame 模拟 python zip::

medias_name <- c("print", "ooh", "tv", "digital")
medias_img <- c("Print.png", "Ooh.png", "Tv.png", "Digital.png")

myenv <- new.env()
zip_df <- data.frame(name=medias_name, img=medias_img, stringsAsFactors=F)
for (i in 1:nrow(zip_df)){
  myenv[[zip_df[i, 'name']]] <- zip_df[i, 'img']
}

所以我们得到::

> zip_df
name         img
1   print   Print.png
2     ooh     Ooh.png
3      tv      Tv.png
4 digital Digital.png

> ls(myenv)
[1] "digital" "ooh"     "print"   "tv"     

> myenv$tv
[1] "Tv.png"
>

另一种解决方案是使用列表模拟 zip 来打包项目::

medias_name <- c("print", "ooh", "tv", "digital")
medias_img <- c("Print.png", "Ooh.png", "Tv.png", "Digital.png")

myenv <- new.env()
ziplist <- list(medias_name, medias_img)
for (i in 1:length(ziplist[[1]])){
    name <- ziplist[[1]][i]
    img <- ziplist[[2]][i]
    myenv[[name]] <- img
}