Converting text files to excel files in R - r

Question

I have radiotelemetry data that is downloaded as a series of text files. I was provided with code in 2018 that looped through all the text files and converted them into CSV files. Up until 2021 this code worked. However, now the below code (specifically the lapply loop), returns the following error:
"Error in setnames(x, value) :
Can't assign 1 names to a 4 column data.table"
# set the working directory to the folder that contain this script, must run in RStudio
setwd(dirname(rstudioapi::callFun("getActiveDocumentContext")$path))
# get the path to the master data folder
path_to_data <- paste(getwd(), "data", sep = "/", collapse = NULL)
# extract .TXT file
files <- list.files(path=path_to_data, pattern="*.TXT", full.names=TRUE, recursive=TRUE)
# regular expression of the record we want
regex <- "^\\d*\\/\\d*\\/\\d*\\s*\\d*:\\d*:\\d*\\s*\\d*\\s*\\d*\\s*\\d*\\s*\\d*"
# vector of column names, no whitespace
columns <- c("Date", "Time", "Channel", "TagID", "Antenna", "Power")
# loop through all .TXT files, extract valid records and save to .csv files
lapply(files, function(x){
df <- read_table(file) # read the .TXT file to a DataFrame
dt <- data.table(df) # convert the dataframe to a more efficient data structure
colnames(dt) <- c("columns") # modify the column name
valid <- dt %>% filter(str_detect(col, regex)) # filter based on regular expression
valid <- separate(valid, col, into = columns, sep = "\\s+") # split into columns
towner_name <- str_sub(basename(file), start = 1 , end = 2) # extract tower name
valid$Tower <- rep(towner_name, nrow(valid)) # add Tower column
file_path <- file.path(dirname(file), paste(str_sub(basename(file), end = -5), ".csv", sep=""))
write.csv(valid, file = file_path, row.names = FALSE, quote = FALSE) # save to .csv
})
I looked up possible fixes for this and found using "setnames(skip_absent=TRUE)" in the loop resolved the setnames error but instead gave the error "Error in is.data.frame(x) : argument "x" is missing, with no default"
lapply(files, function(file){
df <- read_table(file) # read the .TXT file to a DataFrame
dt <- data.table(df) # convert the dataframe to a more efficient data structure
setnames(skip_absent = TRUE)
colnames(dt) <- c("col") # modify the column name
valid <- dt %>% filter(str_detect(col, regex)) # filter based on regular expression
valid <- separate(valid, col, into = columns, sep = "\\s+") # split into columns
towner_name <- str_sub(basename(file), start = 1 , end = 2) # extract tower name
valid$Tower <- rep(towner_name, nrow(valid)) # add Tower column
file_path <- file.path(dirname(file), paste(str_sub(basename(file), end = -5), ".csv", sep=""))
write.csv(valid, file = file_path, row.names = FALSE, quote = FALSE) # save to .csv
})
I'm confused at to why this code is no longer working despite working fine last year? Any help would be greatly appreciated!

Answer 1

The error occured at this line colnames(dt) <- c("columns") where you provided only one value to rename the (supposedly) 4-column dataframe. If you meant to replace a particular column, you can
colnames(dt)[i] <- c("columns")
where i is the index of the column you are renaming. Alternatively, provide a vector with 4 new names.