Skipping rows gets rid off necessary colnames? - r

Question

I've a data frame with some metadata in the first 3 rows, that I need to skip. But doing so, also affects the colnames of the values cols.
What can I do, to avoid opening every CSV on excel and deleting these rows manually?
This is how the CSV looks when opened in Excel:
In R, I'm using this command to open it:
android_per <- fread("...\\Todas las adquisiciones de dispositivos de Versión de Android PE.csv",
skip = 3)
And it looks like this:
UPDATE 1:

Answer 1

Similar logic to #G5W, but I think there needs to be a step of squashing the header that is in 2 rows back to one. E.g.:
txt <- "Some, utter, rubbish,,
Even more rubbish,,,,
,,Col_3,Col_4,Col_5
Col_1,Col_2,,,
1,2,3,4,5
6,7,8,9,0"
## below line writes a file - uncomment if you're happy to do so
##cat(txt, file="testfile.csv", "\n")
header <- apply(read.csv("testfile.csv", nrows=2, skip=2, header=FALSE),
2, paste, collapse="")
read.csv("testfile.csv", skip=4, col.names=header, header=FALSE)
Output:
# Col_1 Col_2 Col_3 Col_4 Col_5
#1 1 2 3 4 5
#2 6 7 8 9 0

Answer 2

Here is one way to do it. Read the file simply as lines of text. Eliminate the lines that you don't want, then read the remaining good part into a data.frame.
Sample csv file (I saved it as "Temp/Temp.csv")
Col_1,Col_2,Col_3,Col_4,Col_5
Some utter rubbish,,,,
Presumably documentation,,,,
1,2,3,4,5
6,7,8,9,0
Code
CSV_Lines = readLines("temp/Temp.csv")
CSV_Lines = CSV_Lines[-(2:3)]
DF = read.csv(text=CSV_Lines)
Col_1 Col_2 Col_3 Col_4 Col_5
1 1 2 3 4 5
2 6 7 8 9 0
It skipped the unwanted lines and got the column names.

Answer 3

If you use skip = 3, you definitely lose the column names without an option to get it back using R. An ugly hack could be to use skip = 2 which will make sure that all other columns except the first 2 are correct.
df <- read.table('csv_name.csv', skip = 2, header = TRUE)
The headers of the first 2 columns are in the first row so you can do
names(df)[1:2] <- df[1, 1:2]
Probably, you need to shift all the rows 1 step up to get dataframe as intended.

Answer 4

In case you put Header as false then you can use below code:
df<-fread("~/Book1.csv", header = F, skip = 2)
shift_up <- function(x, n){
c(x[-(seq(n))], rep(NA, n))
}
df[1,1]<-df[2,1]
df[1,2]<-df[2,2]
df<-df[-2,]
names(df)<-as.character(df[1,])
df<-df[-1,]