[R] Help to download data from multiple URLs with API key

[Eric Berger]

Hi Bhaskar,
Why not just create a function that does the repetitive work, such as

doOne <- function( suffix ) {
   base_url <- "abcd"         # This remains constant
   b <-  "api_key"            # the api key - this remains constant
   c <-  paste("series_id=",suffix,sep="")
   full_url = paste0(base_url, b, c)
   d3 <- lapply(fromJSON(file=full_url)[[2]], function(x) c(x["data"]))
   d3 <- do.call(rbind, d3)
   b <- as.data.frame(unlist(d3))
   write.csv(b)
}

Then,
suffixes <- ... (whatever)
for ( s in suffixes )
    doOne( s )

You might need to also think about the filenames that you want to use in
the write.csv() command in the function doOne.

HTH,
Eric


On Tue, Apr 21, 2020 at 9:30 AM Bhaskar Mitra <bhaskar.kolkata using gmail.com>
wrote:

> Hello Everyone,
>
> I am trying to download data from multiple websites using API key.
> The  code to download from one URL is given below.
>
> I have a list of multiple URLs' where the suffix URL 'c' keeps changing.
>
> I would appreciate any help on how i can modify the code below that will
> allow
>  me to read multiple URLs and save the data from each URL as separate
> csv file.
>
> thanks,
> bhaskar
>
>
> #-----------------------------------------------------------------------
> library(rjson)
> setwd(Input)
>
> base_url <- "abcd"         # This remains constant
>
> b <-  "api_key"            # the api key - this remains constant
>
> c <-  "series_id=1"        # Only this suffix URL changes.  I have a list
> of multiple such URL's with different series ids.
>
>
> full_url = paste0(base_url,
>                   b,
>                   c)
>
>
> d3 <- lapply(fromJSON(file=full_url)[[2]], function(x) c(x["data"]))
> d3 <- do.call(rbind, d3)
>
> b <- as.data.frame(unlist(d3))
> write.csv(b)
>
> #-----------------------------------------------------------------------
>
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>
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