Named Capture Group to create new columns

[magrathean]

How do I create new columns from matches from a named capture group?

df = DataFrame(time = ["twelve:nine", "one:five"])
rx = r"(?<hour>[a-z]*):(?<minute>[a-z]*)"

2×1 DataFrame
 Row │ time        
     │ String      
─────┼─────────────
   1 │ twelve:nine
   2 │ one:three

I want to create:

2×2 DataFrame
 Row │ hour     minute        
     │ String   String
─────┼─────────────
   1 │ twelve nine
   2 │ one    three

Something like the following does not work:

select(df, :time => ByRow(x -> match(rx, x).captures) => AsTable)

[rafael.guerra]

Couldn’t you rename the dataframe and optionally convert the SubStrings to Strings?

df2 = select(df, :time => ByRow(x -> match(rx, x).captures) => AsTable)
rename!(df2, [:hour, :minute])
df2[!,1:2] = convert.(String, df2[!,1:2])

2×2 DataFrame
 Row │ hour    minute 
     │ String  String 
─────┼────────────────
   1 │ twelve  nine
   2 │ one     five

[oxinabox]

Here is the code to create a Tables.jl table (compatible with DataFrames)
With columns based on regex named captures.

Creating a Table from Regex

It occurred to me that it would be nice to be able to create a table from a string by providing a regex that uses named groups. nushell’s parse function (docs, example) does this. A RegexMatch has all the right things for a Tables.jl row, except it doesn’t provide getproperty overloads as historically it’s fields were part of it’s public API (though that has progressively become less true, it would be too breaking to change that now). But we can wrap a RegexMatch in a suitable type. (Might a…

Not sure if that is useful to you.

[magrathean]

Yes, renaming works. If I did use the named captures, renaming seems redundant.

[magrathean]

Thanks. Will check that out.