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](https://www.edureka.co/blog/kafka-streams/#stream)
or
`kvc-df` to convert it to a [pandas dataframe](https://pandas.pydata.org/pandas-docs/stable/getting_started/intro_tutorials/01_table_oriented.html#min-tut-01-tableoriented)
# 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.