Extract location data using regex in R - regex

Question

R newbie here
I have data that looks something like this:
{'id': 19847005, 'profile_sidebar_fill_color': u'http://pbs.foo.com/profile_background', 'profile_text_color': u'333333', 'followers_count': 1105, 'location': u'San Diego, CA', 'profile_background_color': u'9AE4E8', 'listed_count': 43, '009', 'time_zone': u'Pacific Time (US & Canada)', 'protected': False}
I want to extract the location data from this text: San Diego, CA.
I have been trying to use this stringr package to accomplish this, but can't quite get the regex right to capture the city and state. Sometimes state will be present, other times not present.
location_pattern <- "'location':\su'(\w+)'"
rawdata$location <- str_extract(rawdata$user, location_pattern)

Answer 1

You could try
str_extract_all(str1, perl("(?<=location.: u.)[^']+(?=')"))[[1]]
#[1] "San Diego, CA"

Answer 2

Others have given possible solutions, but not explained what likely went wrong with your attempt.
The str_extract function uses POSIX extended regular expressions that do not understand \w and \s, those are specific to Perl regular expressions. You can use the perl function in the stringr package instead and it will then recognize the shortcuts, or you can use [[:space:]] in place of \s and [[:alnum:]_] in place of \w though more likely you will want something like [[:alpha], ] or [^'].
Also, R's string parser gets a shot at the string before it is passed to the matching function, therefore you will need \\s and \\w if you use the perl function (or other regular expressions function in R). the first \ escapes the second so that a single \ remains in the string to be interpreted as part of the regular expression.

Answer 3

It looks like a json string, but if you're not too concerned about that, then perhaps this would help.
library(stringi)
ss <- stri_split_regex(x, "[{}]|u?'|(, '(009')?)|: ", omit=TRUE)[[1]]
(m <- matrix(ss, ncol = 2, byrow = TRUE))
# [,1] [,2]
# [1,] "id" "19847005"
# [2,] "profile_sidebar_fill_color" "http://pbs.foo.com/profile_background"
# [3,] "profile_text_color" "333333"
# [4,] "followers_count" "1105"
# [5,] "location" "San Diego, CA"
# [6,] "profile_background_color" "9AE4E8"
# [7,] "listed_count" "43"
# [8,] "time_zone" "Pacific Time (US & Canada)"
# [9,] "protected" "False"
So now you have the ID names in the left column and the values on the right. It would probably be simple to reassemble the json from this point if need be.
Also, regarding the json-ness, we can coerce m to a data.frame (or leave it as a matrix), and then use jsonlite::toJSON
library(jsonlite)
json <- toJSON(setNames(as.data.frame(m), c("ID", "Value")))
fromJSON(json)
# ID Value
# 1 id 19847005
# 2 profile_sidebar_fill_color http://pbs.foo.com/profile_background
# 3 profile_text_color 333333
# 4 followers_count 1105
# 5 location San Diego, CA
# 6 profile_background_color 9AE4E8
# 7 listed_count 43
# 8 time_zone Pacific Time (US & Canada)
# 9 protected False