replace col names by index or current value

[HarlanH]

something like:

rename!(df, quote
  x1 = "cat"
  x2 = "dog"
end)

rename!(df, {"x1"="cat", "x2"="dog"})

rename!(df, {1="cat", 2="dog"})

rename!(df, ["cat", "dog"]) # must be same length as ncol(df)

rename!(df, function) # allow functional generation of new colname from old one

Note that column name groups should be updated appropriately.

[HarlanH]

oops, didn't see that this was done already! replace_names(df, ...)

[StefanKarpinski]

I would comment that for rename!(df, function) at least, if the function argument goes first, then you can write this:

rename!(df) do name
 # compute new name from old name
end

I realize that in this case that's a somewhat awkward order for the arguments. Just thought I'd point it out.

[tshort]

rename! might be a better name.