Skip specific rows using read.csv in R [duplicate]

问题

I wish to skip the 1st and 3rd rows of my csv file when importing the file into a data frame in R.

In the original file my headers are on line 2.

Using the skip argument in read.csv I can skip the 1st line and set the header argument to TRUE by I still have the 3rd line from the original file in my data frame.

Can anyone suggest how to skip multiple specific rows in R, below is what I was able to cobble together?

Can I pass a vector to the skip argument specifying the exact rows to ignore?

prach <- read.csv("RSRAN104_-_PRACH_Propagation_Delay-PLMN-day-rsran_RU50EP1_reports_RSRAN104_xml-2016_08_23-21_33_03__604.csv", header = TRUE, sep = ",", stringsAsFactors = FALSE, skip = 1)

回答1:

One way to do this is using two read.csv commands, the first one reads the headers and the second one the data:

headers = read.csv(file, skip = 1, header = F, nrows = 1, as.is = T)
df = read.csv(file, skip = 3, header = F)
colnames(df)= headers

I've created the following text file to test this:

do not read
a,b,c
previous line are headers
1,2,3
4,5,6

The result is:

> df
  a b c
1 1 2 3
2 4 5 6

回答2:

My perfect solution:

#' read csv table, wrapper of \code{\link{read.csv}}
#' @description read csv table, wrapper of \code{\link{read.csv}}
#' @param tolower whether to convert all column names to lower case
#' @param skip.rows rows to skip (1 based) before read in, eg 1:3
#' @return returns a data frame
#' @export
ez.read = function(file, ..., skip.rows=NULL, tolower=FALSE){
    if (!is.null(skip.rows)) {
        tmp = readLines(file)
        tmp = tmp[-(skip.rows)]
        tmpFile = tempfile()
        on.exit(unlink(tmpFile))
        writeLines(tmp,tmpFile)
        file = tmpFile
    }
    result = read.csv(file, ...)
    if (tolower) names(result) = tolower(names(result))
    return(result)
}

来源：https://stackoverflow.com/questions/39110755/skip-specific-rows-using-read-csv-in-r

标签

read.csv