使用对象名称重命名存储在列表中的数据框变量

Question

I could not solve a problem despite having studied the related entries. I have a list of many dataframes, each with two columns (variables). I want to rename the second column of each dataframe assigning the name of the dataframe to which it belongs (not including the extension ".csv"). Specifically I need to replace a variable's name with the object's name where the variable is in.

So, for example, I have a list of 3 dataframes

List of 3
 $ Conc.csv1: Classes 'data.table' and 'data.frame':    83 obs of 2 variables.
      .. $ Type: chr [1:83] "FAMILY" ...
      .. $ Process: int [1:83] 2304 ... NA NA

  $ Ambs.csv2: Classes 'data.table' and 'data.frame': 78 obs. of 2 variables:
  .. $ Type: chr [1:78] "CIVIL AND COMMERCIAL" ...
  .. $ Process: int [1:78] NA 2 ...

  $ Sec.csv3: Classes 'data.table' and 'data.frame': 117 obs. of 2 variables:
  .. $ Type: chr [1: 117] "Action"      
  .. $ Process: int [1: 117] NA NA 110 ...

I need the same list but renaming the variable "Process" in every dataframe with the name of the dataframe

So, Output should look like:

List of 3
 $ Conc.csv1: Classes 'data.table' and 'data.frame':    83 obs of 2 variables.
  .. $ Type: chr [1:83] "FAMILY" ...
  .. $ Conc: int [1:83] 2304 ... NA NA

  $ Ambs.csv2: Classes 'data.table' and 'data.frame': 78 obs of 2 variables.
  .. $ Type: chr [1:78] "CIVIL AND COMMERCIAL" ...
  .. $ Ambs: int [1:78] NA 2 ...

  $ Sec.csv3: Classes 'data.table' and 'data.frame' 117 obs of 2 variables.
  .. $ Type: chr [1: 117] "Action"      
  .. $ Sec: int [1: 117] NA NA 110 ...

Answer 1

There are certainly many ways to do this, but I chose the good old for loop:

l <- list(Conc.csv1 = data.frame(Type = NA, Process = NA),
          Ambs.csv1 = data.frame(Type = NA, Process = NA),
          Sec.csv1 = data.frame(Type = NA, Process = NA))

for (df in seq_along(l)) {
  colnames(l[[df]])[2] <- gsub("\\.csv\\d", "", names(l)[df])
}

str(l)
#List of 3
# $ Conc.csv1:'data.frame': 1 obs. of  2 variables:
#  ..$ Type: logi NA
#  ..$ Conc: logi NA
# $ Ambs.csv1:'data.frame': 1 obs. of  2 variables:
#  ..$ Type: logi NA
#  ..$ Ambs: logi NA
# $ Sec.csv1 :'data.frame': 1 obs. of  2 variables:
#  ..$ Type: logi NA
#  ..$ Sec : logi NA

Answer 2

> library("purrr")

> l <- list(Conc.csv1 = data.frame(Type = 1:5, Process = 1:5),
          Ambs.csv1 = data.frame(Type = 6:10, Process = 1:5),
          Sec.csv1 = data.frame(Type = 11:15, Process = 1:5))
> str(l)
List of 3
 $ Conc.csv1:'data.frame':  5 obs. of  2 variables:
  ..$ Type   : int [1:5] 1 2 3 4 5
  ..$ Process: int [1:5] 1 2 3 4 5
 $ Ambs.csv1:'data.frame':  5 obs. of  2 variables:
  ..$ Type   : int [1:5] 6 7 8 9 10
  ..$ Process: int [1:5] 1 2 3 4 5
 $ Sec.csv1 :'data.frame':  5 obs. of  2 variables:
  ..$ Type   : int [1:5] 11 12 13 14 15
  ..$ Process: int [1:5] 1 2 3 4 5

> l_names <- as.list(gsub( "\\.csv1$", "",names(l)))
> l_df <- map2(.x = l, .y = l_names, .f = ~ {colnames(.x)[2] <- .y; return(.x)})

> str(l_df)
List of 3
 $ Conc.csv1:'data.frame':  5 obs. of  2 variables:
  ..$ Type: int [1:5] 1 2 3 4 5
  ..$ Conc: int [1:5] 1 2 3 4 5
 $ Ambs.csv1:'data.frame':  5 obs. of  2 variables:
  ..$ Type: int [1:5] 6 7 8 9 10
  ..$ Ambs: int [1:5] 1 2 3 4 5
 $ Sec.csv1 :'data.frame':  5 obs. of  2 variables:
  ..$ Type: int [1:5] 11 12 13 14 15
  ..$ Sec : int [1:5] 1 2 3 4 5

Answer 3

You could also use lapply as follows. Assuming you have a list named l as in the other examples:

newNames <- gsub("\\..*", "", names(l))
l <- lapply(seq_along(newNames),
            setNames(l[[i]], c(names(l[[i]])[1], newNames[i])))

This will return a list with the data.frames renamed.