> On May 8, 2018, at 10:08 AM, Evans, Richard K. (GRC-H000)
> <richard.k.ev...@nasa.gov> wrote:
>
> Hi David, .. I think I've got it :-)
> Please let me know if you see anything glaringly wrong with this:
>
> library(RCurl)
> zWebObj <- postForm("https://www.semantic-mediawiki.org/w/api.php";,
> "action" = "ask",
> "query" = "[[Category:City]]|?Capital%20of|?Has%20area",
> "format" = "json"
> .opts = list(ssl.verifypeer = FALSE)
> )
>
The R interpreter tells me there's a missing comma after the line:
"format" = "json"
Fixing that syntactic error I get:
str(zWebObj)
# ---bein console output
atomic [1:1]
{"query":{"printrequests":[{"label":"","key":"","redi":"","typeid":"_wpg","mode":2}],"results":{"File:2166320938
| __truncated__
- attr(*, "Content-Type")= Named chr [1:2] "application/json" "utf-8"
..- attr(*, "names")= chr [1:2] "" "charset"
#--- end console output-----
js1 <-fromJSON(zWebObj)
#--------
Error: lexical error: inside a string, '\' occurs before a character which it
may not.
title":""}},"serializer":"SMW\Serializers\QueryResultSeriali
(right here) ------^
I'm not really a JSON expert, so am not equipped to offer debugging assistance
there.
--
David.
> Thank you!
> -Rich
>
> -----Original Message-----
> From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of Evans,
> Richard K. (GRC-H000)
> Sent: Tuesday, May 08, 2018 12:51 PM
> To: David Winsemius
> Cc: r-help@r-project.org
> Subject: Re: [R] help with json data from the web into data frame in R
>
> [non-tabular json data] -- ok.. so I think I need to figure out how to make
> it tabular. Thanks!
>
> [curl] -- I was hoping there was a cleaner way to do it.. using R to evoke
> cURL to get the data as text and then passing it into getJSON seems to be
> what I need to do.
>
> Do you by chance have an simple example of using RCurl to get a response
> ignoring cert errors?
>
> ty
> -Rich
>
> -----Original Message-----
> From: David Winsemius [mailto:dwinsem...@comcast.net]
> Sent: Tuesday, May 08, 2018 12:25 PM
> To: Evans, Richard K. (GRC-H000)
> Cc: r-help@r-project.org
> Subject: Re: [R] help with json data from the web into data frame in R
>
>
>> On May 8, 2018, at 9:03 AM, Evans, Richard K. (GRC-H000)
>> <richard.k.ev...@nasa.gov> wrote:
>>
>> That said, I have two issues to ask for help with:
>>
>> 1) how to ignore cert errors with a fromJSON call
>
> If you can do it with curl, then why aren't you doing one of a) a system
> call, b) installing and loading RCurl, c) installing and loading curl (the R
> package with that name)?
>
>>
>> And
>>
>> 2) why the json data from the example link doesn't convert to a data frame.
>
> That was already answered in my earlier response. It's not a tabular result,
> so it doesn't "fit" into a tabular structure.
>
> --
> David.
>
>
>> As seen in the following example
>>
>> library("rjson")
>> result <- fromJSON(file =
>> "https://www.semantic-mediawiki.org/w/api.php?action=ask&query=[[Category:City]]|?Capital%20of|?Has%20area&format=json")
>> json_data_frame <- as.data.frame(result)
>> print(json_data_frame)
>>
>> which results in:
>>
>>> library("rjson")
>>
>> Warning message:
>> package ‘rjson’ was built under R version 3.4.4
>>
>>> result <- fromJSON(file =
>>> "https://www.semantic-mediawiki.org/w/api.php?action=ask&query=[[Category:City]]|?Capital%20of|?Has%20area&format=json")
>>> json_data_frame <- as.data.frame(result)
>>
>> Error in (function (..., row.names = NULL, check.rows = FALSE, check.names =
>> TRUE, :
>> arguments imply differing number of rows: 0, 1
>>
>>> print(json_data_frame)
>>
>> Error in print(json_data_frame) : object 'json_data_frame' not found
>>
>>>
>>
>> -----Original Message-----
>> From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of Evans,
>> Richard K. (GRC-H000)
>> Sent: Tuesday, May 08, 2018 11:52 AM
>> To: David Winsemius
>> Cc: r-help@r-project.org
>> Subject: Re: [R] help with json data from the web into data frame in R
>>
>> Right. I'm trying to access a server within my organization which has a cert
>> error that I cannot fix.
>>
>> The example link I provided was to a site on the web that does not have the
>> cert error.
>>
>> From the linux shell I use the "-k" switch with cURL to ignore cert errors..
>> is there an equivalent in the R world?
>>
>> -Rich
>>
>>
>> -----Original Message-----
>> From: David Winsemius [mailto:dwinsem...@comcast.net]
>> Sent: Tuesday, May 08, 2018 11:48 AM
>> To: Evans, Richard K. (GRC-H000)
>> Cc: Eric Berger; r-help@r-project.org
>> Subject: Re: [R] help with json data from the web into data frame in R
>>
>>
>>> On May 8, 2018, at 8:36 AM, Evans, Richard K. (GRC-H000)
>>> <richard.k.ev...@nasa.gov> wrote:
>>>
>>> I’ve been tinkering and discovered that the link I need to read json data
>>> from is ‘https’ and there is a certificate warning that I have to click
>>> through from a browser. That might be my issue. Is there any way in the
>>> json package to tell it to ignore self-signed cert errors in a url?
>>
>> I didn't have that issue when using the link you offered:
>>
>> library(jsonlite)
>> myJSON <- fromJSON(
>> url("https://www.semantic-mediawiki.org/w/api.php?action=ask&query=%5B%5BCategory:City%5D%5D&format=json";)
>> )
>>
>> # results in a complex list (not trivially reducible to a dataframe:
>>
>> str(myJSON)
>> List of 1
>> $ query:List of 5
>> ..$ printrequests:'data.frame': 1 obs. of 5 variables:
>> .. ..$ label : chr ""
>> .. ..$ key : chr ""
>> .. ..$ redi : chr ""
>> .. ..$ typeid: chr "_wpg"
>> .. ..$ mode : int 2
>> ..$ results :List of 39
>> .. ..$ File:2166320938 5cfc9ec72a z.jpg :List of 6
>> .. .. ..$ printouts : list()
>> .. .. ..$ fulltext : chr "File:2166320938 5cfc9ec72a z.jpg"
>> .. .. ..$ fullurl : chr
>> "https://www.semantic-mediawiki.org/wiki/File:2166320938_5cfc9ec72a_z.jpg";
>> #-----trimmed-----------
>>
>> David
>>
>>>
>>> -Rich
>>>
>>> From: Eric Berger [mailto:ericjber...@gmail.com]
>>> Sent: Tuesday, May 08, 2018 11:31 AM
>>> To: Evans, Richard K. (GRC-H000)
>>> Cc: r-help@r-project.org
>>> Subject: Re: [R] help with json data from the web into data frame in R
>>>
>>> Hi Rich,
>>> Take a look at the function fromJSON found in the rjson package.
>>> Note that the Usage in the help page: ?fromJSON names the second
>>> argument 'file' but if you look at the description the argument can be a
>>> URL.
>>>
>>> HTH,
>>> Eric
>>>
>>>
>>> On Tue, May 8, 2018 at 6:16 PM, Evans, Richard K. (GRC-H000)
>>> <richard.k.ev...@nasa.gov<mailto:richard.k.ev...@nasa.gov>> wrote:
>>> Hello
>>>
>>> I am able to construct a url that points to some data online in the JSON
>>> format. See an example at [0].
>>>
>>> I would like to work with this data as a dataframe in R.
>>>
>>> I know that there is a package for handling json data [1] but it assumes
>>> the data is in a local file but It is not clear to me how to request the
>>> data from the web in an R script and get the json data converted into a
>>> data frame in R.
>>>
>>> Can anyone provide a basic example or some guidance please?
>>>
>>> -Rich (revansx)
>>>
>>> [0]
>>> https://www.semantic-mediawiki.org/w/api.php?action=ask&query=[[Catego
>>> ry:City]]&format=json<https://www.semantic-mediawiki.org/w/api.php?act
>>> ion=ask&query=%5b%5bCategory:City%5d%5d&format=json>
>>> [1] https://www.tutorialspoint.com/r/r_json_files.htm
>>>
>>> ______________________________________________
>>> R-help@r-project.org<mailto:R-help@r-project.org> mailing list -- To
>>> UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help
>>> PLEASE do read the posting guide
>>> http://www.R-project.org/posting-guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
>>>
>>>
>>> [[alternative HTML version deleted]]
>>>
>>> ______________________________________________
>>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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>>> PLEASE do read the posting guide
>>> http://www.R-project.org/posting-guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
>>
>> David Winsemius
>> Alameda, CA, USA
>>
>> 'Any technology distinguishable from magic is insufficiently advanced.'
>> -Gehm's Corollary to Clarke's Third Law
>>
>>
>>
>>
>>
>> ______________________________________________
>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>
> David Winsemius
> Alameda, CA, USA
>
> 'Any technology distinguishable from magic is insufficiently advanced.'
> -Gehm's Corollary to Clarke's Third Law
>
>
>
>
>
> ______________________________________________
> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
David Winsemius
Alameda, CA, USA
'Any technology distinguishable from magic is insufficiently advanced.'
-Gehm's Corollary to Clarke's Third Law
______________________________________________
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
![https://www.semantic-mediawiki.org/wiki/File:2166320938_5cfc9ec72a_z.jpg"](https://www.semantic-mediawiki.org/wiki/File:2166320938_5cfc9ec72a_z.jpg"){kind=link}