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

[Bhaskar Mitra]

Hi Eric,

Thanks for your help. This is really helpful.
I have also adjusted the code to ensure  filename has the
base url and suffix as strings.

thanks,
bhaskar

On Tue, Apr 21, 2020 at 12:16 AM Eric Berger <ericjberger using gmail.com> wrote:

> 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)
>>
>> #-----------------------------------------------------------------------
>>
>>         [[alternative HTML version deleted]]
>>
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>

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