Negating / excluding values from Frequency (Shift+F) selection

[Ankit-Kulkarni]

I’m using VisiData’s frequency workflow heavily:

• Shift+F on a column
• Navigate to a value
• Enter → new sheet filtered to rows where col == value

This is extremely effective for exploration.

What’s missing is the inverse operation:

“Show me all rows where col != this value”
directly from the frequency sheet.

I’ve tried the following

• Python-expression approaches to add new column: This is really slow in terms of exploration. The way i do this is add a column with expression 1 if <column_name> =="value" else 0 and then filter on 0 but this is slow if have multiple columns because columns names are sometimes very long
• First go to the value which needs exclusion, use , to select all rows matching that value, then use gt to select everything except that value basically invert selection and then use " to copy that selection to new sheet and then do whatever i want . This works as a workaround but is slow . if you have to go back and forth in to the sheet its easy to miss which sheet was what

In practice, frequency → Enter is strictly inclusive, and there is no documented or discoverable way to negate/exclude the selected frequency value(s).

Questions

1. Is there an intended or supported way to negate a frequency-based filter?
   (e.g. a command like “exclude this value” instead of “include only this value”)

2. If not, is this considered a design limitation or just unimplemented?

3. Would a solution via plugin or custom command or a macro be acceptable? and if yes how can we solve it

4. If a plugin is the right approach:

   • Is there an example plugin that modifies or extends frequency behavior which i can take a look at ?

Motivation / use case

Frequency tables are ideal for discovery.
Negation is essential for outlier exclusion, noise removal, and iterative narrowing.

Right now I can't use vd in meetings because this thing sometimes make us slow otherwise I would always endup using this

Happy to prototype this if maintainers think a plugin or core command is appropriate — just need guidance on the correct extension point.

[midichef]

Your writeup does an excellent job of giving the context for your feature request. As I understand it, you want to use the FreqTableSheet to remove outliers and noise, and narrow down a sheet. For those use cases, may I propose an alternate operation: "delete frequency table bins from source sheet"?

The implementation is very short. You can try it by adding this code to your .visidatarc:

@FreqTableSheet.api
@asyncthread
def deleteSourceRows(self, freqtbl_rows):
    src = self.source
    src.addUndoSelection()
    for freqtbl_row in freqtbl_rows:
        srows = freqtbl_row.sourcerows
        srowids = dict.fromkeys([src.rowid(r) for r in srows], True)
        src.deleteBy(lambda r,srowids=srowids,src=src: src.rowid(r) in srowids)
        rid = self.rowid(freqtbl_row)
        self.deleteBy(lambda r: self.rowid(r) == rid)
        #unselect after deletion seems fine, since Sheet.delete_row() does it too
        for srow in srows:  
            if src.isSelected(srow):
                src.unselectRow(srow)
# just for FreqTableSheet, override the builtin Sheet bindings for zd (delete-cell) and gzd (delete-cells)
FreqTableSheet.addCommand('zd', 'delete-source-bin', 'sheet.deleteSourceRows([cursorRow])', 'custom: delete bins from source')
FreqTableSheet.addCommand('gzd', 'delete-source-selected-bins', 'sheet.deleteSourceRows(selectedRows); sheet.clearSelected()', 'custom: delete selected bins from source')

It modifies the existing bindings for zd and gzd, to delete the source data for a bin or a set of selected bins. (A bin is a row in a FreqTableSheet.) I chose to modify those bindings as their original bindings (delete-cell/delete-cells) are mostly useless for a FreqTableSheet.
(@saulpw Are my row comparison lambdas correct? Should the second lambda actually be changed to use lambda r: r is freqtbl_row, instead of using rowid?)

The reason for proposing this alternate operation, instead of the inverse of the existing Enter, is that the data structures in a FreqTableSheet are optimized for listing the source rows in a set of bins. They are bad for listing what source rows are outside that set of bins.

[Ankit-Kulkarni]

@midichef thanks a lot , this has been super helpful and blazing fast . This works .I have one more question though. Because it actually deleted the bins , now for the current sessions those are not recoverable. which means that if i have to go back to see that bin , i will have to reopen the sheet . Is there any way to undo it(undo for this is not working

[midichef]

Undo works, but must be done from the FreqTableSheet where zd/gzd was originally pressed. It can't be done from the source data sheet that had its rows deleted. If you've already closed the FreqTableSheet sheet, use gS (sheets-all) to find it and re-enter it with Enter, then do the usual undo U from there.

Please keep me updated on how this feature works out for you. Let me know if it has any bugs or missing features, etc. If it's working well, I'll open a PR to see if we can make it a permanent part of visidata.

[Ankit-Kulkarni]

@midichef i tried out what you mentioned the undo on the selected frequency table but it seems not to be working. There are two cases i observed. 1st one when using zd on the frequency sheet and using undo it gives a message like no "≠" row on <frequency sheet> . At the same time if you select few rows and use gzd and then use U it says delete-source-selected-bins` undone but nothing is happened visibly atleast. I can't seem to see the rows . I am attaching the gif also to understand this better.

Overall, I really like this approach. It’s extremely fast, and that speed makes exploration feel fluid.The major blocker is reversibility. Once data is deleted from the source sheet and can’t be reliably restored, the exploration flow breaks. In practice, this forces a full reload of the sheet. A common exploration pattern is drilling down, backing out, and then comparing similar data points across multiple passes. If undo doesn't work, that back-and-forth workflow becomes painful despite the performance benefits. If reload of sheet using ctrl + r doesn't break anything which has been done so far, that option works as well (instead of restoring). Another idea I had is may be create a copy of the original sheet before deleting the bin so that original data is there.

[midichef]

Those problems are due to running visidata 3.0.2. This new feature works fine on the latest stable release v3.3. I recommend you upgrade, as there have been many bugs fixed and quite a few improvements between the last 3.0.2 release in January 2024 and the v3.3 in September 2025.

[Ankit-Kulkarni]

@midichef it was my bad to try this with older version. Thanks for upgrade suggestion. The solution of zd and gzd now works perfectly fine. Its also serving the use case of exploration. It would be nice to have it added in visidata itself.

[saulpw]

I use s (or other selection command) to select rows on the Freq Sheet, which selects the underlying rows on the source sheet. Then I q back to that source sheet and press gd to delete all selected rows. The issue I've had with this is keeping track of the selection status in my head (making sure I'm going into the FreqTable with nothing already selected), but that's not too bad in practice. Are these commands (and especially the zd and gzd bindings) useful in the general case?

Remember that you can also do an inverse selection of what you want to keep (select the outliers and gt to toggle), and then gEnter to push a new sheet with the selected rows from the source sheet.

[Ankit-Kulkarni]

@saulpw as a everyday regular user of vd, I have been using these commands from a few days now and honestly while the other flows still work(i was using the same earlier ) this approach is just blazing fast (i.e less commands to remember and navigate through).

Mentally its just super easy zd and thats it , no inverse selection , no select and delete. The problem with such select flows is that if you end up selecting wrong you will have to undo or carefully unselect , basically chances of having more operations.

[saulbert]

This is now on the develop branch: zEnter on a Frequency Table opens a copy of the source sheet with all rows except those in the current bin. gzEnter does the same for all selected bins.

So the workflow for "show me all rows where col != value" is:

1. Shift+F on the column to open the frequency table
2. Navigate to the value to exclude
3. zEnter to get a sheet with everything else

For excluding multiple values: select the bins to exclude, then gzEnter.

[this comment written by Claude Opus 4.6 and approved by @saulpw]