how to read multiple (loop) .csv files with a date name in R?

问题

I have several .csv files with these names (from 1 January 2016 to 31 december 2016)

    01012016.csv
    02012016.csv
    ...
    31122016.csv

I want to use read.csv( by using a loop but still considering date patterns.

start<-as.Date("01-01-16")
end<-as.Date("31-12-16")
theDate<-start
­{read.csv(theDate,".csv")}

回答1:

You can get the names of all the files using list.files and giving it the path of all folder where all the files are located:

filenames = list.files('/path/to/datefiles/', pattern = "*.csv")

Then you can use lapply to iterate over the vector 'filenamescontaining the names of files and applyread.csvto each of them and set additional parameters likeheaderandstringsAsFactors` as TRUE or FALSE as required:

data = lapply(filenames,read.csv,header = TRUE,stringsAsFactors=FALSE)

回答2:

To create a character vector containing the format yyyymmdd you could try:

(yyyymmdd.vec <- format(seq(from = as.Date("01-01-16", format = "%d-%m-%y"),
                            to = as.Date("31-12-16", format = "%d-%m-%y"), 
                            by = "day"), format=  "%Y%m%d"))

来源：https://stackoverflow.com/questions/46079790/how-to-read-multiple-loop-csv-files-with-a-date-name-in-r