r-如何将具有多个工作表的多个工作簿中的数据读取到R中？

Question

我正在尝试使用r从具有多个工作表的 多个工作簿中读取数据。 有10个工作簿，每个工作簿都有两个工作表中的数据。

以下代码可用于从第一张工作表中提取数据。 但是，我也想将数据提取到同一工作簿中的另一张纸上。 我不确定如何在以下代码中指定工作表名称。

library(purrr)
library(readxl)
library(dplyr)
library(tidyr)

data_path <- "C:/Desktop/Test"

files <- dir(data_path, pattern = "*.xlsx")


weights_data <- data.frame(filename = files) %>%
               mutate(file_contents = map(filename,
                                                 ~ read_excel(file.path
                                                              (data_path,  .))))

View(unnest(weights_Data))

Answer 1

read_excel另一个参数，可让您指定特定的工作表：

sheet: Sheet to read. Either a string (the name of a sheet), or an
       integer (the position of the sheet). Ignored if the sheet is
       specified via 'range'. If neither argument specifies the
       sheet, defaults to the first sheet.

这样，我们需要扩展您的路径框架以包括工作表，这可以通过readxl::excel_sheets轻松完成，对于单个路径，它返回工作表名称的向量。

反复进行讨论/演练，尽管只需要最后一个块：

library(tibble)
library(dplyr)
library(tidyr)
library(purrr)
library(readxl)

data_frame(
  path = list.files(path = "~/StackOverflow/Prah/", pattern = "*.xlsx", full.names = TRUE)
) %>%
  mutate(sheets = map(path, excel_sheets))
# # A tibble: 3 x 2
#   path                                        sheets   
#   <chr>                                       <list>   
# 1 "C:\\Users\\r2/StackOverflow/Prah/mt1.xlsx" <chr [2]>
# 2 "C:\\Users\\r2/StackOverflow/Prah/mt2.xlsx" <chr [2]>
# 3 "C:\\Users\\r2/StackOverflow/Prah/mt3.xlsx" <chr [2]>

仅此一项并不能立即带来帮助，但我们可以unnest它的unnest ：

data_frame(
  path = list.files(path = "~/StackOverflow/Prah/", pattern = "*.xlsx", full.names = TRUE)
) %>%
  mutate(sheets = map(path, excel_sheets)) %>%
  unnest(sheets)
# # A tibble: 6 x 2
#   path                                        sheets
#   <chr>                                       <chr> 
# 1 "C:\\Users\\r2/StackOverflow/Prah/mt1.xlsx" Sheet1
# 2 "C:\\Users\\r2/StackOverflow/Prah/mt1.xlsx" Sheet2
# 3 "C:\\Users\\r2/StackOverflow/Prah/mt2.xlsx" Sheet1
# 4 "C:\\Users\\r2/StackOverflow/Prah/mt2.xlsx" Sheet2
# 5 "C:\\Users\\r2/StackOverflow/Prah/mt3.xlsx" Sheet1
# 6 "C:\\Users\\r2/StackOverflow/Prah/mt3.xlsx" Sheet2

现在应该清楚的是，我们现在只需要使用map2或类似的对象遍历每一行，就可以得到一个嵌套整齐的数据框：

data_frame(
  path = list.files(path = "~/StackOverflow/Prah/", pattern = "*.xlsx", full.names = TRUE)
) %>%
  mutate(sheets = map(path, excel_sheets)) %>%
  unnest(sheets) %>%
  mutate(data = map2(path, sheets, ~ read_excel(path = .x, sheet = .y)))
# # A tibble: 6 x 3
#   path                                        sheets data              
#   <chr>                                       <chr>  <list>            
# 1 "C:\\Users\\r2/StackOverflow/Prah/mt1.xlsx" Sheet1 <tibble [32 x 11]>
# 2 "C:\\Users\\r2/StackOverflow/Prah/mt1.xlsx" Sheet2 <tibble [32 x 11]>
# 3 "C:\\Users\\r2/StackOverflow/Prah/mt2.xlsx" Sheet1 <tibble [32 x 11]>
# 4 "C:\\Users\\r2/StackOverflow/Prah/mt2.xlsx" Sheet2 <tibble [32 x 11]>
# 5 "C:\\Users\\r2/StackOverflow/Prah/mt3.xlsx" Sheet1 <tibble [32 x 11]>
# 6 "C:\\Users\\r2/StackOverflow/Prah/mt3.xlsx" Sheet2 <tibble [32 x 11]>

（我写了几张excel工作簿，每本都有两张纸，每张纸上都有mtcars 。没什么。）