取消列出数据框中的列并列出 [英] Unlist column in data frame with listed

问题描述

我有一个包含多个级别的列表，我希望将数据级别放入一个数据帧中，其中变量chr折叠为单个字符串.

I have a list with multiple levels that I would like to the data level into a data frame, where the variable chr is collapsed into single strings.

 myList <- list(total_reach = list(4),
                   data = list(list(reach = 2,
                              chr = list("A", "B", "C"),
                              nr = 3,
                              company = "Company A"),
                   list(reach = 2,
                        chr = list("A", "B", "C"),
                        nr = 3,
                        company = "Company B")))

我想将其转换为如下所示的数据框:

I would like to transform this into a data frame that looks like this:

  reach     chr nr   company
1     2 A, B, C  3 Company A
2     2 A, B, C  3 Company B

使用dplyr和data.table，我已经走了这么远.

Using dplyr and data.table I've come this far.

library(data.table)
library(dplyr)
df <- data.frame(rbindlist(myList[2])) %>% t() %>% as.data.frame()

colnames(df) <- names(myList$data[[1]])
rownames(df) <- c(1:nrow(df))

df$chr <- as.character(df$chr)

df <- df %>%
  mutate_all(funs(unlist(.recursive = F, use.names = F)))

但是，chr列包含带"list()"的字符串.

However, chr column contains strings with "list()" wrapped around it.

  reach                 chr nr   company
1     2 list("A", "B", "C")  3 Company A
2     2 list("A", "B", "C")  3 Company B

A)是否有更好的方法可以取消列出此类列表并将其转换为数据框?
B)如何将chr中的列表折叠为字符串或因子?

A) Is there a better way to unlist this kind of list and turn it into a data frame?
B) How do I collapse the lists in chr to strings or factors?

推荐答案

使用 data.table ，您可以尝试

library(data.table)
rbindlist(lapply(myList$data, as.data.table))[, .(chr = toString(chr)), 
                                              by = .(reach, nr, company)]

   reach nr   company     chr
1:     2  3 Company A A, B, C
2:     2  3 Company B A, B, C

---

请注意，使用 as.data.table 或 as.data.frame 会有所不同:

rbindlist(lapply(myList$data, as.data.table))

   reach chr nr   company
1:     2   A  3 Company A
2:     2   B  3 Company A
3:     2   C  3 Company A
4:     2   A  3 Company B
5:     2   B  3 Company B
6:     2   C  3 Company B

rbindlist(lapply(myList$data, as.data.frame))

   reach chr..A. chr..B. chr..C. nr   company
1:     2       A       B       C  3 Company A
2:     2       A       B       C  3 Company B

---

或者，在将列表转换为数据表之前，可以操作 chr .

rbindlist(lapply(myList$data, function(x) {
    x$chr = toString(x$chr)
    return(as.data.table(x))
}))

   reach     chr nr   company
1:     2 A, B, C  3 Company A
2:     2 A, B, C  3 Company B

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