如何使用 purrr:map() 從多個 excel 文件中讀取工作表？

Question

我有一個帶有文件路徑列和工作表名稱列的小標題（為安全起見，刪除了路徑）：

x <- structure(list(file = c("2003_2005_DataDictionary.xlsx", "2003_2005_DataDictionary.xlsx", 
"2003_2005_DataDictionary.xlsx", "2003_2005_DataDictionary.xlsx", 
"2003_2005_DataDictionary.xlsx", "2003_2005_DataDictionary.xlsx", 
"1996_2002_DataDictionary.xlsx", "1996_2002_DataDictionary.xlsx", 
"1996_2002_DataDictionary.xlsx", "1996_2002_DataDictionary.xlsx", 
"1996_2002_DataDictionary.xlsx", "1996_2002_DataDictionary.xlsx", 
"1996_2002_DataDictionary.xlsx", "1996_2002_DataDictionary.xlsx", 
"1996_2002_DataDictionary.xlsx", "1996_2002_DataDictionary.xlsx", 
"1996_2002_DataDictionary.xlsx", "1996_2002_DataDictionary.xlsx", 
"1996_2002_DataDictionary.xlsx", "1996_2002_DataDictionary.xlsx"
), sheet = c("vartable05", "vartable04", "vartable03", "valuesets05", 
"valuesets04", "valuesets03", "vartable02", "vartable01", "vartable00", 
"vartable99", "vartable98", "vartable97", "vartable96", "valuesets02", 
"valuesets01", "valuesets00", "valuesets99", "valuesets98", "valuesets97", 
"valuesets96")), class = c("tbl_df", "tbl", "data.frame"), row.names = c(NA, 
-20L))

> x
# A tibble: 20 x 2
   file                          sheet      
   <chr>                         <chr>      
 1 2003_2005_DataDictionary.xlsx vartable05 
 2 2003_2005_DataDictionary.xlsx vartable04 
 3 2003_2005_DataDictionary.xlsx vartable03 
 4 2003_2005_DataDictionary.xlsx valuesets05
 5 2003_2005_DataDictionary.xlsx valuesets04
 6 2003_2005_DataDictionary.xlsx valuesets03
 7 1996_2002_DataDictionary.xlsx vartable02 
 8 1996_2002_DataDictionary.xlsx vartable01 
 9 1996_2002_DataDictionary.xlsx vartable00 
10 1996_2002_DataDictionary.xlsx vartable99 
11 1996_2002_DataDictionary.xlsx vartable98 
12 1996_2002_DataDictionary.xlsx vartable97 
13 1996_2002_DataDictionary.xlsx vartable96 
14 1996_2002_DataDictionary.xlsx valuesets02
15 1996_2002_DataDictionary.xlsx valuesets01
16 1996_2002_DataDictionary.xlsx valuesets00
17 1996_2002_DataDictionary.xlsx valuesets99
18 1996_2002_DataDictionary.xlsx valuesets98
19 1996_2002_DataDictionary.xlsx valuesets97
20 1996_2002_DataDictionary.xlsx valuesets96

我需要使用read_excel()讀取每個工作表並將其合並為一個數據框，但是以下代碼不起作用：

x %>% 
   map_dfr(~read_excel(path = .$file, sheet = .$sheet))
#Error in .$file : $ operator is invalid for atomic vectors
```

What am I doing wrong? I've tried imap as well with no luck.

Answer 1

我們可以將map2用於每列的相應元素

library(purrr)
map2(x$file, x$sheet, ~ read_excel(path = .x, sheet = .y)

或者用pmap

pmap(x, ~ read_excel(path = ..1, sheet = ..2))

或者如果我們重命名列，

x %>%
   rename(path = file) %>%
   pmap(read_excel)