使用pdf提取器循环并添加到R中的数据帧

Question

I want to read in a pdf via pdf tools, extract some data from it and write it to a csv. I have been able to do this successfully for one pdf, but I have many (440) to do. I'm trying to write a loop that goes through a list I have created that has all my file paths in it. The problem is it overwrites every time. So I think my program is doing what I've asked of it, but I am not asking the correct thing! My code is below:

temp <-as.list(list.files(pattern = "*.pdf"))

file_path <- file.path(getwd(),temp)%>%as.list()

data_anz<-as.character()

for (i in 1:length(file_path)){
  data_anz<-pdf_text(file_path[[i]])[2]%>%str_split("\n")%>%.[[1]]%>%str_split_fixed("\\s{2,}", n=4)%>%as.data.frame(i:length(file_path))%>%rename(Commodity =V1, Level = V2, Change = V3, Description = V4)

}

What I would like achieve is a data frame that adds to with every iteration, not over writes. So first run, the df = 1 row, 4 cols, the next run 2 rows ect.

I'm lost! But I can get it to work for an individual member of the list and it seems to work through the whole list, but overwrites.

Any help would be super appreciated!

Answer 1

Each iteration of the loop is assigning your table to the same variable. You might want to try something like

data_anz<-list()

for (i in 1:length(file_path)){
data_anz[[i]] <- ...
}
data_anz_all <- do.call(data_anz, rbind)

which puts each table into its own position in a list, and then row-binds them all together at the end (assuming the columns of the individual frames are compatible).