How do I use conditional cell formatting with R in an .xlsx file created with R?

I have created the following r script to extract data from various pdf files and create an excel file. I'd like to be able to do a conditional formatting (fill in the cells with colours) according to threshold values in my column 3 (Escherichia coli) and 4 (enterococci) but I can't find a correct script or the beginnings of an answer. Can you help me?


Set the source folder path where the PDF files are located

folder_path <- "path/Données estivales EDP"

Get a list of PDF files in the folder

pdf_files <- list.files(folder_path, pattern = "\.pdf$", full.names = TRUE)

Create an empty list to store the data frames

dfs <- list()

Loop through each PDF file

for (pdf_file in pdf_files) {

Convert the PDF to plain text

text <- pdf_text(pdf_file)

Split the text into individual lines

lines <- unlist(strsplit(text, "\n"))

#Filter lines containing specific keywords
filtered_lines <- lines[grepl("Escherichia coli par microplaque|Entérocoques intestinaux par microplaque|Date de prélèvement|Adresse :", lines, = TRUE)]

Split each filtered line into columns based on spaces

split_lines <- lapply(filtered_lines, function(line) unlist(strsplit(line, "\s+")))

Determine the maximum number of columns

max_cols <- max(lengths(split_lines))

Create a data frame with a fixed number of columns

df <-"", nrow = length(split_lines), ncol = max_cols))

Fill the data frame with the split lines

for (i in seq_along(split_lines)) {
if (split_lines[[i]][1] == "") {
df[i, 1] <- paste0(split_lines[[i]][2], " ", split_lines[[i]][3])
df[i, 4:length(split_lines[[i]])] <- split_lines[[i]][4:length(split_lines[[i]])]
} else {
df[i, 1:length(split_lines[[i]])] <- split_lines[[i]]

Reorganize variables

df[df[, 1] == "Date", 2] <- df[df[, 1] == "Date", 5]
df[df[, 1] == "Date", 5] <- ""

df[df[, 1] == "Adresse", 2] <-apply(df[df[, 1] == "Adresse", 3:max_cols],1, function(x) paste(x,collapse=" "))

df[df[, 1] == "Escherichia coli", 2]<-df[df[, 1] == "Escherichia coli", 6]
df[df[, 1] == "Entérocoques intestinaux", 2]<-df[df[, 1] == "Entérocoques intestinaux", 6]


Transpose the data frame

df <-, stringsAsFactors = FALSE)

Set the first row as variable names

names(df) <- df[1, ]
df <- df[-1, ]

Reshape the data frame

reshaped_df <- matrix(df, nrow = ncol(df)/4, ncol = 4, byrow = TRUE)

Convert the reshaped matrix back to a data frame

df_new <-
df_new<-sapply(df_new,function(x) as.character(x))
df_new <-
df_new$Escherichia coli <- as.numeric(df_new$Escherichia coli)
df_new$Entérocoques intestinaux <- as.numeric(df_new$Entérocoques intestinaux)

Append the data frame to the list

dfs[[pdf_file]] <- df_new

Combine all data frames into a single data frame

combined_df <-, dfs)

Set the path for the output Excel file

output_file <- "path/Données estivales EDP/Extraction_données_EDP.xlsx"

Write the combined data frame to an Excel file

write_xlsx(combined_df, output_file)

I do not see any way to do conditional formatting with the writexl package. It can be done with the openxlsx package.

Take a look at the conditionalFormatting() function in the reference manual of the package. If you need more specific help, please post the output of


and explain what threshold values you want to use on the two columns.

Thank you for your reply. Unfortunately I tried using the openxlsx library and it didn't work. My colour code is : for column Escherichia coli red for >= 1000, yellow for >=500 & <1000 and green for <500, for column Enteroccocci red for >= 400, yellow for >=200 & <400 and green for <200.

For the output It's complicated because it involves private data...

I invented some data to work with. I hope it matches what you are working with. If it does not, please post some invented data that better matches your needs.
The following code adds conditional formatting to the second column. I could not find a way to apply the condition >= 500 & <1000, so I approximated it with >= 500 & <= 999.9999.

combined_df <- data.frame(Name = LETTERS[1:10],
                          `Escherichia coli` = runif(10, min = 0, max = 2000))

wb <- createWorkbook()
addWorksheet(wb, sheetName = "FirstSheet")
writeData(wb, sheet = "FirstSheet", x = combined_df)
RedStyle <- createStyle(bgFill = "red")
YellowStyle <- createStyle(bgFill = "yellow")
GreenStyle <- createStyle(bgFill = "green")
conditionalFormatting(wb, sheet = "FirstSheet", cols = 2, 
                      rows = 2:(nrow(combined_df)+1),
                      type = "expression", 
                      rule = ">= 1000", 
                      style = RedStyle)
conditionalFormatting(wb, sheet = "FirstSheet", cols = 2, 
                      rows = 2:(nrow(combined_df)+1),
                      type = "between", 
                      rule = c(500, 999.9999),
                      style = YellowStyle)
conditionalFormatting(wb, sheet = "FirstSheet", cols = 2, 
                      rows = 2:(nrow(combined_df)+1),
                      type = "expression", 
                      rule = "< 500", 
                      style = GreenStyle)
saveWorkbook(wb, "CondFormat.xlsx", overwrite = TRUE)

1 Like

This topic was automatically closed 42 days after the last reply. New replies are no longer allowed.

If you have a query related to it or one of the replies, start a new topic and refer back with a link.