Extract string from csv file after reading in Prolog - csv

Good evening,
I am trying to read a csv file in Prolog containing all the countries in the world. Executing this code:
read_KB(R) :- csv_read_file("countries.csv",R).
I get a list of Terms of this type:
R = [row('Afghanistan;'), row('Albania;'), row('Algeria;'), row('Andorra;'), row('Angola;'), row('Antigua and Barbuda;'), row('Argentina;'), row('Armenia;'), row(...)|...].
I would like to extract only the names of each country in form of a String and put all of them into a list of Strings.
I tried this way with only the first row executing this:
read_KB(L) :- csv_read_file("/Users/dylan/Desktop/country.csv",R),
give(R,L).
give([X|T],X).
I obtain only a Term of type row('Afghanistan;')

You can use maplist/3:
read_KB(Names) :-
csv_read_file('countries.csv', Rows, [separator(0';)]),
maplist([row(Name,_), Name] >> true, Rows, Names).

The answer given by #slago can be simplified, using arg/3 instead of a lambda expression, making it slightly more efficient:
read_KB(Names) :-
csv_read_file('countries.csv', Rows, [separator(0';)]),
maplist(arg(1), Rows, Names).

Related

Returning MySQL data as an OBJECT rather than an ARRAY (Knex)

Is there a way to get the output of a MySQL query to list rows in the following structure
{
1:{voo:bar,doo:dar},
2:{voo:mar,doo:har}
}
as opposed to
[
{id:1,voo:bar,doo:dar},
{id:2,voo:mar,doo:har}
]
which I then have to loop through to create the desired object?
I should add that within each row I am also concatenating results to form an object, and from what I've experimented with you can't group_concatenate inside a group_concatenation. As follows:
knex('table').select(
'table.id',
'table.name',
knex.raw(
`CONCAT("{", GROUP_CONCAT(DISTINCT
'"',table.voo,'"',':','"',table.doo,'"'),
"}") AS object`
)
.groupBy('table.id')
Could GROUP BY be leveraged in any way to achieve this? Generally I'm inexperienced at SQL and don't know what's possible and what's not.

How do I search for a specific string in a JSON Postgres data type column?

I have a column named params in a table named reports which contains JSON.
I need to find which rows contain the text 'authVar' anywhere in the JSON array. I don't know the path or level in which the text could appear.
I want to just search through the JSON with a standard like operator.
Something like:
SELECT * FROM reports
WHERE params LIKE '%authVar%'
I have searched and googled and read the Postgres docs. I don't understand the JSON data type very well, and figure I am missing something easy.
The JSON looks something like this.
[
{
"tileId":18811,
"Params":{
"data":[
{
"name":"Week Ending",
"color":"#27B5E1",
"report":"report1",
"locations":{
"c1":0,
"c2":0,
"r1":"authVar",
"r2":66
}
}
]
}
}
]
In Postgres 11 or earlier it is possible to recursively walk through an unknown json structure, but it would be rather complex and costly. I would propose the brute force method which should work well:
select *
from reports
where params::text like '%authVar%';
-- or
-- where params::text like '%"authVar"%';
-- if you are looking for the exact value
The query is very fast but may return unexpected extra rows in cases when the searched string is a part of one of the keys.
In Postgres 12+ the recursive searching in JSONB is pretty comfortable with the new feature of jsonpath.
Find a string value containing authVar:
select *
from reports
where jsonb_path_exists(params, '$.** ? (#.type() == "string" && # like_regex "authVar")')
The jsonpath:
$.** find any value at any level (recursive processing)
? where
#.type() == "string" value is string
&& and
# like_regex "authVar" value contains 'authVar'
Or find the exact value:
select *
from reports
where jsonb_path_exists(params, '$.** ? (# == "authVar")')
Read in the documentation:
The SQL/JSON Path Language
jsonpath Type

Python: How to combine the results of for loop into one output which extracted from json file?

I extracted some values from Json file and the result is as follow.
[92.21372509012637]
[92.21372509012637]
[240.3532913296266]
[240.3532913296266]
[240.3532913296266]
[240.3532913296266]
I would like to get the result in a single list. as follow.
[92.21372509012637, 92.21372509012637, 240.3532913296266, 240.3532913296266, 240.3532913296266, 240.3532913296266]
Following is some part of my code.
for i in range(len(response_i['objcontent'][0]['rowvalues'])):
lat = response_i['objcontent'][0]['rowvalues'][i][0]
decoded=base64.b64decode(lat)
if len(decoded)<9:
a=struct.unpack('d',decoded)
result=[]
for i in a:
result.append(i)
print (result)
any one knows how can I fix this issue?
Thank you.

Logstash - Substring from CSV column

I want to import many informations from a CSV file to Elastic Search.
My issue is I don't how can I use a equivalent of substring to select information into a CSV column.
In my case I have a field date (YYYYMMDD) and I want to have (YYYY-MM-DD).
I use filter, mutate, gsub like:
filter
{
mutate
{
gsub => ["date", "[0123456789][0123456789][0123456789][0123456789][0123456789][0123456789][0123456789][0123456789]", "[0123456789][0123456789][0123456789][0123456789]-[0123456789][0123456789]-[0123456789][0123456789]"]
}
}
But my result is false.
I can indentified my string but I don't how can I extract part of this.
My target it's to have something like:
gsub => ["date", "[0123456789][0123456789][0123456789][0123456789][0123456789][0123456789][0123456789][0123456789]","%{date}(0..3}-%{date}(4..5)-%{date}"(6..7)]
%{date}(0..3} : select from the first to the 4 characters of csv columns date
You can use ruby plugin to do conversion. As you say, you will have a date field. So, we can use it directly in ruby
filter {
ruby {
code => "
date = Time.strptime(event['date'],'%Y%m%d')
event['date_new'] = date.strftime('%Y-%m-%d')
"
}
}
The date_new field is the format you want.
First, you can use a regexp range to match a sequence, so rather than [0123456789], you can do [0-9]. If you know there will be 4 numbers, you can do [0-9]{4}.
Second, you want to "capture" parts of your input string and reorder them in the output. For that, you need capture groups:
([0-9]{4})([0-9]{2})([0-9]{2})
where parens define the groups. Then you can reference those on the right side of your gsub:
\1-\2-\3
\1 is the first capture group, etc.
You might also consider getting these three fields when you do the grok{}, and then putting them together again later (perhaps with add_field).

MySQL Query and POSIXct in Loop

I have the following MySQL Query using RMySQL. All the Database parameters are set before and Query is working well. Is there a possibility to put it in a loop to get multiple zoo objects from more than one dpname? Thanks!
dpname.df<-"%Name%"
paste.query.df<-paste("select handle from db.connect where dpname like '",dpname.df,"'",sep='')
handle.df<-dbGetQuery(dbLT,paste.query.df)
paste.query2.df<-paste("select time,value from db.data where handle='",handle.df,"' and time between '",x,"' and '",y,"'",sep='')
df <- dbGetQuery(dbLT,paste.query2.df)
df$time<-as.POSIXct(df$time,format="%Y-%m-%d %H:%M:%S")
df.zoo<-zoo(df[,-1],df[,1])
I tried to set a function with mapply:
query<-function(x,y,dpname.df)
{
paste.query.df<-paste("select handle from db.connect where dpname like '",dpname.df,"'",sep='')
handle.df<-dbGetQuery(dbLT,paste.query.df)
paste.query2.df<-paste("select time,value from db.data where handle='",handle.df,"' and time between '",x,"' and '",y,"'",sep='')
dbGetQuery(dbLT,paste.query2.df)
}
which I can run: with mapply(query,x,y,dpname.df)
But I can't get multiple outputs for each! query. Is it possible to set another List with the output names? So I could also put the zoo and POSIXct stuff in my function.Thanks!