Extract all dataframes from a list which contains certain columns-CodePudding

I have a list like:

Name <- c("Jon", "Bill", "Maria", "Ben", "Tina")
Age <- c(23, 41, 32, 58, 26)
Hight <- c(13, 41, 32, 58, 26)
Weight <- c(11,43,23,43,123)

df1 <- data.frame(Name, Age, Hight, Weight)
df2 <- data.frame(Name, Age, Hight)
df3<- data.frame(Name, Age, Weight)

l <- list(df1, df2, df3)

I want now to extract all dataframes (or the name of the dataframes), which contain the Hight andWeight columns.

The expected output in this case would list(df1)

CodePudding user response：

You can use this

l <- list(df1, df2, df3)

l[sapply(l , \(x) all(c('Weight', 'Hight') %in% colnames(x)))]

output

[[1]]
   Name Age Hight Weight
1   Jon  23    13     11
2  Bill  41    41     43
3 Maria  32    32     23
4   Ben  58    58     43
5  Tina  26    26    123

CodePudding user response：

Purrr comes with keep() / discard():

dfs <- list(df1, df2, df3)

purrr::keep(dfs, ~ all(c("Hight", "Weight") %in% colnames(.x)))
#> [[1]]
#>    Name Age Hight Weight
#> 1   Jon  23    13     11
#> 2  Bill  41    41     43
#> 3 Maria  32    32     23
#> 4   Ben  58    58     43
#> 5  Tina  26    26    123

CodePudding user response：

One possible way is using a for loop:

dfs <- list(df1, df2, df3)

n <- length(dfs)
index <- NULL # index of dataframes to be used
for (i in 1:n){
  if ("Hight" %in% names(dfs[[i]]) & "Weight" %in%  names(dfs[[i]]))
    index <- c(index, i)
}

dfs[index]

CodePudding user response：

df_list <- list(df1, df2, df3)
have_all_columns <- purrr:::map_lgl(df_list, ~all(c( "Hight", "Weight") %in% names(.x)))
df_list[have_all_columns]