Implement `janitor::clean_names()`

[kdpsingh]

This would be nice functionality to have. In R, this function cleans up column names in data frames, replacing spaces with underscores as well as a few other things.

Per https://cran.r-project.org/web/packages/janitor/vignettes/janitor.html#clean-dataframe-names-with-clean_names, here's what this function does:

• Parses letter cases and separators to a consistent format.
• Default is to snake_case, but other cases like camelCase are available
• Handles special characters and spaces, including transliterating characters like œ to oe.
• Appends numbers to duplicated names
• Converts “%” to “percent” and “#” to “number” to retain meaning
• Spacing (or lack thereof) around numbers is preserved

[werkstattcodes]

fyi - Maybe not new, there is a julia package with basically the same intention. Could be helpful.

https://github.com/TheRoniOne/Cleaner.jl

[kdpsingh]

Ooh I wasn't aware! Thank you for sharing. Let me review and see if there's any value to wrapping or re-exporting this.

[kdpsingh]

Actually, this package looks like it does the job. I don't think there's a need for us to build this out. I'm going to add a Resources section in our documentation to point to other packages that people coming from R may find helpful. I'll add this one there and then will close the issue.

[kdpsingh]

Resolved by #68. Implemented the @clean_names macro that wraps Cleaner.jl’s polish_names() function. Unlike polish_names(), the @clean_names() macro expects the optional case argument to be a string rather than a symbol, always returns a data frame, and can handle grouped data frames, in which the result is a grouped data frame.