BurntSushi/xsv

Select columns based on regex

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#155 opened on Oct 28, 2018

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 (4 comments) (0 reactions) (0 assignees)Rust (9,730 stars) (315 forks)batch import
enhancementhelp wanted

Description

I have a pretty unwieldy CSV file with a ton of columns (~300000) all with quite long column names. I'd really like to be able to select the columns using a regex rather than having to attempt to figure out a set of ranges from the header. Is this a feature you think would fit in xsv?

I'm not sure exactly what the input would look like; perhaps an additional flag to indicate that the selection(s) are regexes?

Thanks so much for all your work, by the way! :smiley:

Edit: forgot to say, I'd be happy to have a go at implementing this!

Contributor guide

Tech stack
rust
Domain
clitooling
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
basic Rust knowledgefamiliarity with regexunderstanding of xsv's codebase
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
50
Research direction
Investigate the xsv codebase to understand how column selection currently works (likely via index or name). Look at the CLI argument parsing in src/main.rs and the select command implementation. Explore the regex crate for Rust. The issue suggests an additional flag like regex to indicate regex patterns. Consider the performance implications of regex matching across 300,000 columns. Review any existing comments in the issue for further requirements or constraints.