CSV文件可以用于下载URL中的多个zip文件吗？

这是一个应该起作用的小循环：

df <- data.frame(all_dates = c("20150711","20160613")) 
dates <- unique(df$all_dates) # create list of dates that you want

for (d in dates){ # each 'd' is one date

# create url to download from for each date
download.file(paste0("https://www.quandl.com/api/v3/databases/OSMV/download?download_type=", d, "&api_key=my_api_key", 

# create destination file with date in the file name
destfile = paste0("/Users/anders/Documents/Juni 2019/DATA/datatest", d, ".zip", 
mode="wb", method="libcurl"))
}