Cannot remove rows from data.frame [duplicate] - r

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This question already has answers here:
How do I deal with special characters like \^$.?*|+()[{ in my regex?
(2 answers)
Closed 2 years ago.
I have a series of excel files and I have been using this basic code to import my data for a very long time now. I have not made any changed to the data or the code, but I not read the data properly anymore. I read the files as follow:
apply_fun <- function(filename) {
data <- readxl::read_excel(filename, sheet = "Section Cut Forces - Design",
skip = 1, col_names = TRUE)
data <- data[-1,]
data <- subset(data, StepType == "Max")
data <- data[,c(1,2,6,10)]
data$id <- filename
return(data)
}
filenames <- list.files(pattern = "\\.xlsx", full.names = TRUE)
first <- lapply(filenames,apply_fun)
out <- do.call(rbind,first)
The first few rows of out look like:
structure(list(SectionCut = c("1", "1", "1", "1", "1", "2", "2",
"2", "2", "2"), OutputCase = c("Service (after losses)", "LL-1",
"LL-2", "LL-3", "LL-4", "Service (after losses)", "LL-1", "LL-2",
"LL-3", "LL-4"), V2 = c("11.522", "28.587", "42.246000000000002",
"44.212000000000003", "36.183", "9.8469999999999995", "23.989000000000001",
"37.408999999999999", "43.401000000000003", "40.450000000000003"
), M3 = c("299728.66100000002", "42863.517999999996", "63147.332999999999",
"69628.464000000007", "59196.74", "0", "27.942", "44.863999999999997",
"46.31", "36.204999999999998"), id = c("./100-12-S00.xlsx", "./100-12-S00.xlsx",
"./100-12-S00.xlsx", "./100-12-S00.xlsx", "./100-12-S00.xlsx",
"./100-12-S00.xlsx", "./100-12-S00.xlsx", "./100-12-S00.xlsx",
"./100-12-S00.xlsx", "./100-12-S00.xlsx")), row.names = c(NA,
-10L), class = c("tbl_df", "tbl", "data.frame"))
I try to remove rows as:
out2 <- out[!grep("Service (after losses)", out$OutputCase),]
but the result is 0 observations.
I must say that this just started being an issue for me. I have been able to run this code successfully for months now and never had an issue.

Answer 1

() are special symbols in regex. They have special meaning when you use them in functions like grep/grepl etc. You can use fixed = TRUE in grep to match them exactly. Also ! should be used with grepl and - should be used with grep to remove rows.
out[-grep("Service (after losses)", out$OutputCase, fixed = TRUE),]
Apart from that this looks like an exact match so why use pattern matching with grep? Try :
out[out$OutputCase != 'Service (after losses)', ]