This crate / package is a rust module that handles streaming input and output. It's purpose is to tally or accumulate values for a streaming set of keys. It is designed to be stupidly simple and consume / produce whitespace seperate values.

Key Value Counts

I use this library to parse simple journal-like logs where each line is of the form:

2021-03-01 warnings:3 error ... (other items with optional counts)

Supposing I wanted to do some processing on this data. This is a very readable / writeable format, but is not standard.

We can use kvc-stream to covert it into something more lika a stream of k-value pairs or kvc-df to convert it to a pandas dataframe

Spec

The kvc journal format is very simple.

• Each line is a "frame"
• A frame has an optional "date header"
• A frame is composed of a string of whitespace-seperated keys with optional counts per key
• A '#' ends the frame, and is useful for comments

These are valid frames, one per line:

a event event 2021-04-01 april_fools_pranks:4 2021-03-01 key another_key a-third-key <weird-symbols_ar_ok!> this_has_occured_three_times:3 this_twice this_twice 2021-04-02 # Nothing happened that day

Suppose that's stored in data.txt. (try it!)

Running <data.txt kvc-stream produces:

1 a 1 2 event 2 3 Date 2021-04-01 3 april_fools_pranks 4 4 Date 2021-03-01 4 <weird-symbols_ar_ok!> 1 4 a-third-key 1 4 this_has_occured_three_times 3 4 this_twice 2 4 key 1 4 another_key 1 5 Date 2021-04-02

Running cat data.txt | kvc-df (or < data.txt kvc-df ) produces:

Idx april_fools_pranks this_twice a <weird-symbols_ar_ok!> event Date a-third-key key this_has_occured_three_times another_key 1 N/A N/A 1 N/A N/A N/A N/A N/A N/A N/A 2 N/A N/A N/A N/A 2 N/A N/A N/A N/A N/A 3 4 N/A N/A N/A N/A 2021-04-01 N/A N/A N/A N/A 4 N/A 2 N/A 1 N/A 2021-03-01 1 1 3 1 5 N/A N/A N/A N/A N/A 2021-04-02 N/A N/A N/A N/A

OK, so I actually aligned the text with cat data.txt | kvc-dv | column -t

I use this to keep a journal of events and easily scrape it for analysis in other programs or databases.