将 data.frame 的列从列表转换为向量

Question

我有一个使用代码从列表“y”创建的 data.frame

map_dfr(y, ~as.data.frame(t(.x))) 

该格式对我有用，但数据框的每一列本身就是一个列表，而不是我想要的向量。我可以做些什么来展平每个列表，以便保留数据框的结构，但更改每列的格式？

编辑：这是当前格式的一小部分数据。我想要做的是将每个变量取消列出到一个向量中，因此它采用正常的 data.frame 格式。

structure(list(member_id = list("A000055", "A000361", "A000367", 
"A000369", "A000210", "B001256", "B000013", "B001279", "B001269", 
"B001282"), name = list("Robert B. Aderholt", "Rodney Alexander", 
"Justin Amash", "Mark Amodei", "Robert E. Andrews", "Michele Bachmann", 
"Spencer Bachus", "Ron Barber", "Lou Barletta", "Andy Barr"), 
party = list("R", "R", "R", "R", "D", "R", "R", "D", "R", 
    "R"), state = list("AL", "LA", "MI", "NV", "NJ", "MN", 
    "AL", "AZ", "PA", "KY"), district = list("4", "5", "3", 
    "2", "1", "6", "6", "2", "11", "6"), cook_pvi = list(
    NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, 
    NULL), vote_position = list("No", "Yes", "No", "Yes", 
    "Yes", "No", "Yes", "Yes", "Yes", "Yes"), dw_nominate = list(
    0.361, 0.331, 0.649, 0.376, -0.297, 0.584, 0.387, -0.123, 
    0.277, 0.485), bill_num = c("S47", "S47", "S47", "S47", 
"S47", "S47", "S47", "S47", "S47", "S47"), bill_title = c("Violence Against Women Reauthorization Act of 2013", 
"Violence Against Women Reauthorization Act of 2013", "Violence Against Women Reauthorization Act of 2013", 
"Violence Against Women Reauthorization Act of 2013", "Violence Against Women Reauthorization Act of 2013", 
"Violence Against Women Reauthorization Act of 2013", "Violence Against Women Reauthorization Act of 2013", 
"Violence Against Women Reauthorization Act of 2013", "Violence Against Women Reauthorization Act of 2013", 
"Violence Against Women Reauthorization Act of 2013")), row.names = c(NA, 10L), class = "data.frame")

Answer 1

也许，这就是你想要的：

y[] <- lapply(y, unlist)

这会将数据转换为正常的 data.frame 格式。

str(y)
#'data.frame':  10 obs. of  9 variables:
# $ member_id    : chr  "A000055" "A000361" "A000367" "A000369" ...
# $ name         : chr  "Robert B. Aderholt" "Rodney Alexander" "Justin Amash" "Mark Amodei" ...
# $ party        : chr  "R" "R" "R" "R" ...
# $ state        : chr  "AL" "LA" "MI" "NV" ...
# $ district     : chr  "4" "5" "3" "2" ...
# $ vote_position: chr  "No" "Yes" "No" "Yes" ...
# $ dw_nominate  : num  0.361 0.331 0.649 0.376 -0.297 0.584 0.387 -0.123 0.277 0.485
#$ bill_num     : chr  "S47" "S47" "S47" "S47" ...
# $ bill_title   : chr  "Violence Against Women Reauthorization Act of 2013" "Violence Against Women Reauthorization Act of 2013" "Violence Against Women Reauthorization Act of 2013" "Violence Against Women Reauthorization Act of 2013" ...

---

如果我们有多个长度的列表，我们可以使用unnest 并传递一系列列。

library(tidyr)
library(dplyr)

z <- y %>% 
       unnest(cols = member_id:district)  %>%
       type.convert(as.is = TRUE) %>%
       arrange(desc(district))

我们可以使用arrange(district) 对它们进行升序排序。