z' currently resets the cache on a column, but it could freeze the column like this instead. This would be more in-line with the rest of the ' commands anyway. I'm fine with leaving cache-col without a binding since I think this new command might itself work in the rare instances I've needed it.

Many times I want to replace a column with it's frozen version, so it would be useful to me. This would save some steps. I haven't tried the sample code. Would the prefrozen column still exist as hidden? If not, it would be useful to rename it to something different, like with a suffix (uf -- unfrozen, pf - prefrozen, ...) I like that your example makes the frozen version the same name as the original column.

It would be nice if this command:

• is undoable
• handles the case when the original column is materializing such as when it is still async evaluating values.

This replace original column feature would be useful with other commands that return a new modified version of another column.

@frosencrantz
Here's a version that keeps the prefrozen column, as a hidden column with the suffix '_unfrozen'. It'll work if you add it to your .visidatarc.

It is undoable. But it does not handle the case of freezing a column that is still materializing. I'm not sure that can be done.

@BaseSheet.api
def setcol_freeze(sheet):
    unfrozen = sheet.cursorCol
    frozen = sheet.freeze_col(unfrozen)
    frozen.name = unfrozen.name
    unfrozen.hide()
    vd.addUndoColNames([unfrozen])
    unfrozen.name = frozen.name + '_unfrozen'
    sheet.addColumnAtCursor(frozen)
    vd.status(f'replaced {frozen.name} with frozen copy')
Sheet.addCommand("z'", 'setcol-freeze', 'setcol_freeze()', 'replace current column with a frozen copy, with all cells evaluated')

Let me know if you have any feedback.

I will try this. Thank you!

@midichef this is very nice. I have two feedback comments:

1. There is no visual feedback. After you call the command everything looks the same. To be sure it was successful I went to the ColumnsSheet. If VisiData had some sort of animation support, you could temporarily highlight and unhighlight the column. Maybe a vd.status() message saying that the column is now frozen. As I use it more, maybe that would not be needed, but for my first attempts I wasn't sure. As an aside, it is odd that a frozen column can be modified, and one of the reasons to freeze a generated column is to modify the values. The "unfrozen" column is the one that cannot be directly modified.
2. The undo is not complete. It leaves the original column with the "_unfrozen" suffix. Not sure if that is fixable, but that seems wrong. If you undo, and then do it again, the _unfrozens are additive: "_unfrozen_unfrozen..."

@frosencrantz
Good suggestions. I edited the code snippet above to address your comments. I added a vd.status() message as feedback. And I fixed the undo to restore the column's original name.