For Loop in R import multiple CSV from URL - r

Question

I am importing 500 csv's that have the following similar format:
"https://www.quandl.com/api/v3/datasets/WIKI/stockname/data.csv?column_index=11&transform=rdiff&api_key=keyname"
Where stockname is the ticker symbol of a single stock. I have the list of stock tickers saved in a dataframe called stocklist.
I'd like to use lapply to iterate through my list of stocks. Here's what I have so far:
lst <- lapply(stocklist, function(i){
url <- paste0("https://www.quandl.com/api/v3/datasets/WIKI/",i,"/data.csv?column_index=11&transform=rdiff&api_key=XXXXXXXXXXXXXXX")
spdata <- read.csv(url, stringsAsFactors = FALSE)
})
I get the following error:
Error in file(file, "rt") : invalid 'description' argument
What could be causing this error? I tried using a for loop as well, but was unsuccessful and I have been told lapply is a better method in R for this type of task.
Edit:
Stucture of stocklist:
> dput(droplevels(head(stocklist)))
structure(list(`Ticker symbol` = c("MMM", "ABT", "ABBV", "ABMD",
"ACN", "ATVI")), .Names = "Ticker symbol", row.names = c(NA,
6L), class = "data.frame")
Second Edit (solution):
stockdata<-lapply(paste0("https://www.quandl.com/api/v3/datasets/WIKI/",stocklist[1][[1]],"/data.csv?column_index=11&transform=rdiff&api_key=XXXXXXX"),read.csv,stringsAsFactors=FALSE)
Add names to stockdata:
names(stockdata)<-stocklist[1][[1]]

Answer 1

I believe your 'i' variable is a vector.
Make sure you are sub-scripting it properly and only passing one stock at a time.
This: i would look something like this: i[x]

Answer 2

I can't tell what i is, but I'm guessing it's a number. Can you try this and see if it works for you? I think it's pretty close. Just make sure the URL matches the pattern of the actual URL you are fetching data from. I tried to find it; I couldn't find it.
seq <- c(1:10)
for (value in seq) {
mydownload <- function (start_date, end_date) {
start_date <- as.Date(start_date) ## convert to Date object
end_date <- as.Date(end_date) ## convert to Date object
dates <- as.Date("1970/01/01") + (start_date : end_date) ## date sequence
## a loop to download data
for (i in 1:length(dates)) {
string_date <- as.character(dates[i])
myfile <- paste0("C:/Users/Excel/Desktop/", string_date, ".csv")
string_date <- gsub("-", "-", string_date) ## replace "-" with "/"
myurl <- paste("https://www.quandl.com/api/v3/datasets/WIKI/", i, "/data.csv?column_index=11&transform=rdiff&api_key=xxxxxxxxxx", sep = "")
download.file(url = myurl, destfile = myfile, quiet = TRUE)
}
}
}