如何在R中循环浏览列表 [英] How to loop through a list in R

问题描述

我有一个清单可以说:

dataSet$mixed_bag <- list("Hello", c("USA", "Red", "100"), c("India", "Blue", "76"))

我想遍历此列表并根据列表的内容创建新的变量.伪代码看起来像这样.

I want to iterate through this list and create new variables based on the contents of the list. A pseudo code would look something like this.

foreach row in dataSet$mixed_bag {
    if (sapply(dataSet$mixed_bag, length) == 3) {
        dataSet$country <- dataSet$mixed_bag[[row]][1];
        dataSet$color <- dataSet$mixed_bag[[row]][2];
        dataSet$score <- dataSet$mixed_bag[[row]][3];
    } else if (sapply(dataSet$mixed_bag, length) == 2) {
       #Do something else
    } else {
       # Do nothing
    }
}

请提出我将如何在R中做到这一点

Please suggest how would I do this in R

推荐答案

类似的东西?

dataList=list("Hello", c("USA", "Red", "100"), c("India", "Blue", "76"))
for(i in dataList){print(i)}

返回:

[1] "Hello"
[1] "USA" "Red" "100"
[1] "India" "Blue"  "76"   

或:

for(i in dataList){for(j in i){print(j)}}

返回:

[1] "Hello"
[1] "USA"
[1] "Red"
[1] "100"
[1] "India"
[1] "Blue"
[1] "76"

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