Remove characters from the last column of a list of data frame-CodePudding

I have a list listDF of 30 data frames (~1000 rows X 3 columns). In the last column of each one, I have a composite character as shown below :

Date        Origin              Chemical
28/10/2012  Artificial nuclides Cs-137__Sea
28/10/2012  Natural nuclides    Ra-226__Clouds
28/10/2012  Natural nuclides    Ra-228__Sands
28/10/2012  Natural nuclides    Th-228__Sea
28/10/2012  Artificial nuclides Cs-137__Rocks

For the last column of each df, how can I simply remove "__Sea", "__Clouds"... and just keep the chemical name ?

CodePudding user response：

Base R solution:

## requires R version 4.1 or higher
listDF = lapply(listDF,
  \(df) {
    df[["Chemical"]] = sub(pattern = "__.*", replacement = "", df[["Chemical"]])
    df
  })

## any R version
listDF = lapply(listDF,
  function(df) {
    df[["Chemical"]] = sub(pattern = "__.*", replacement = "", df[["Chemical"]])
    df
  })

CodePudding user response：

For-loop solution:

for (i in 1:nrow(listDF)){
  listDF[i, "Chemical"] = unlist(strsplit(listDF[i, "Chemical"], "__"))[1]
}