New symbol .KEY that refers to the key of data table
Nobody has claimed this yet.
Assessment
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Newbie friendliness
- 35/100
Research direction
Start by reviewing data.table's existing handling of table keys and the by argument, then compare the requested behavior with the linked Stack Overflow question. Done means the example using .KEY groups by the data table key and produces the expected result.
Written by the indexing model from the issue text.
Description
It would be useful and more elegant (IMHO) to refer to the key of the data table with .KEY symbol:
x <- data.table(mtcars, key='cyl')
x[, .(mean=mean(mpg)), by=.KEY]
A StackOverflow questions where I asked about this is here: http://stackoverflow.com/questions/43589505/refering-to-the-key-of-data-table-in-by-argument-not-using-key
- Dominant language
- R
- Stars
- 3.9k
- Forks
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- Avg merge
- 14h 4m
- Merged PRs (30d)
- 4
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
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- Open a pull request that references the issue number.
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