Export dataframes from a list into a folder using write.csv

Question

Edited for clarity and reproduciblity....

I have a list of dataframes that I want to export to a folder on my PC via a file path. Doing this one at a time, or writing multiple 'write.csv' commands is possible, but repetitive. Is there a way that I could use a for loop to export my data frames from that list using a single command?

example data:

m1 <- matrix(c(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 
               75, 10, 36, 36, 23, 55, 56, 24, 22, 66,
               -7.8, -5.6, -2, -4.1, -8.4, -3, -4.2, -4, 0.1, -3), nrow = 10) 
df <- as.data.frame(m1)  
split_n <- 5 
dlist <- split(df, factor(sort(rank(row.names(df))%%split_n))) 
names(dlist) <- paste0("site_data", 1980:1984)
dlist

I can do the following, one file at a time:

write.csv(dataList$table_1,"C:/filepath/dataframe_name_1.csv", row.names = F)

But doing this for hundreds of files isn't exactly efficient.

What I want to do is send the five data frames (site_data1980 : site_data1984) along my filepath to the folder on my PC as a list of named csv files.

Julien · Accepted Answer · 2022-11-18 09:22:58Z

1

lapply(seq_along(dataList), \(i) write.csv(dataList[[i]], paste0("C:/filepath/dataframe_name_", i, ".csv"), row.names = F))

edited Nov 18, 2022 at 9:22

answered Nov 18, 2022 at 9:15

Julien

1,8881 gold badge15 silver badges33 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Bob Over a year ago

There is some error in this. I get a warning "unexpected '\'" and "expected ',' after expression"

Julien Over a year ago

Which version of R do you use?

Julien Over a year ago

Replace \(i) with function(i)

Julian · Accepted Answer · 2022-11-18 12:40:30Z

0

You could try something like this

filepath <- "C:/filepath/dataframe_name_"

purrr::imap(dlist, ~write.csv(x = .x, file = paste0(filepath,  
                              readr::parse_number(.y), ".csv"), 
                              row.names = FALSE))

edited Nov 18, 2022 at 12:40

answered Nov 18, 2022 at 9:18

Julian

9,6452 gold badges20 silver badges43 bronze badges

6 Comments

Bob Over a year ago

This does two strange things. Firstly it only saves the first 8 out of 31 files. Secondly it converts the data frame contents into a single column in the output csv files.

Julian Over a year ago

Bob, have a look at this. It is very difficult to help you, when we have limited information. For instance could you post dput(dataList$table_1) and maybe an example dataframe such that we can reproduce your issue.

Bob Over a year ago

Understood. Reproducible example added to my question.

Julian Over a year ago

check my edit, for the MWE it works.

Bob Over a year ago

It works, thanks. I do wonder, the files are saved as "file1.csv, file2.csv" etc. Is there a way to replace the "1","2", with year numbers to match the names in the list?

|

Collectives™ on Stack Overflow

Export dataframes from a list into a folder using write.csv

2 Answers 2

3 Comments

6 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

6 Comments

Your Answer

Sign up or log in

Post as a guest

Related