Accessing nested json object

[balki]

I am trying to parse this

❯ cat uaexp.jsonl           
{"level":"info","request":{"method":"GET","headers":{"User-Agent":["Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; GPTBot/1.2; +https://openai.com/gptbot)"]}},"bytes_read":0,"user_id":"","duration":0.007523876,"size":9939,"status":200}

user agent (ua) is not printed but method is ok.

❯ mlr --l2p --from uaexp.jsonl put '$m = $request.method; $ua = $request.headers["User-Agent"][1]' then cut -of level,m,ua,size,status                                                                     
level m   size status                                                                                                                                                                                              
info  GET 9939 200                                                                                                                                                                                                 

Changing .headers to ["headers"], makes it work.

❯ mlr --l2p --from uaexp.jsonl put '$m = $request.method; $ua = $request["headers"]["User-Agent"][1]' then cut -of level,m,ua,size,status                                                                  
level m   ua                                                                                                     size status                                                                                       
info  GET Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; GPTBot/1.2; +https://openai.com/gptbot) 9939 200                                                                                          

It looks like mixing . and [] way of accessing does not work. Is this intentional?

[johnkerl]

Yes, it's intentional ... the Miller DSL handles data structures coming from Python but its syntax isn't the same as say that of jq.