R — Cleaning/Merging Excel files

This is just a useful snippet of code I’ve been using a lot to tidy
up messy exports I’ve been getting lately.

Takes in a bunch of excel files, rewrites some variable column names in
column 3 then outputs them as a list of dataframes. These then get
merged into a single csv file.

filenames <- list.files("excels", pattern="*.xlsx", full.names=TRUE)
ldf <- lapply(filenames, function(file) {
df = read.xls(file)
names = names(df)
sectionName = names[3]
names(df)[names(df)==sectionName] <- "section"
result = reshape::merge_all(ldf)
write.csv(result, "result.csv", row.names=FALSE)