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.evans at 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:ericjberger at gmail.com] Sent: Tuesday, May 08, 2018 11:31 AM To: Evans, Richard K. (GRC-H000) Cc: r-help at 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.evans at nasa.gov<mailto:richard.k.evans at 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=[[Category:City]]&format=json<https://www.semantic-mediawiki.org/w/api.php?action=ask&query=%5b%5bCategory:City%5d%5d&format=json> [1] https://www.tutorialspoint.com/r/r_json_files.htm
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