Relocate

(dataframe-relocate df names [where anchor])

returns: a dataframe where the columns in the names are moved, by default, to the front of all columns in df. Optionally, indicate where columns should be placed relative to the anchor column. Valid options for where are 'before and 'after.

> (define df
    (make-df*
     (a 1 2 3)
     (b 4 5 6)
     (c 7 8 9)
     (d 10 11 12)))

> (dataframe-display df)

 dim: 3 rows x 4 cols
       a       b       c       d
   <num>   <num>   <num>   <num>
      1.      4.      7.     10.
      2.      5.      8.     11.
      3.      6.      9.     12.

> (dataframe-display
    (dataframe-relocate df '(c d)))

 dim: 3 rows x 4 cols
       c       d       a       b
   <num>   <num>   <num>   <num>
      7.     10.      1.      4.
      8.     11.      2.      5.
      9.     12.      3.      6.

> (dataframe-display
    (dataframe-relocate df '(a) 'after 'c))

 dim: 3 rows x 4 cols
       b       c       a       d
   <num>   <num>   <num>   <num>
      4.      7.      1.     10.
      5.      8.      2.     11.
      6.      9.      3.     12.

> (dataframe-display
    (dataframe-relocate df '(d c) 'before 'b))

 dim: 3 rows x 4 cols
       a       d       c       b
   <num>   <num>   <num>   <num>
      1.     10.      7.      4.
      2.     11.      8.      5.
      3.     12.      9.      6.