Safe oneliners!

[redraw]

I had a domain and zone columns, for which I wanted to create a new one from a expression that lookup their IPs.

I found out this lib: result, so that I could wrap the expression and unwrap it with some default value if it fails. I would import socket, result from System > Python > import library and then create the column,

=result.as_result(Exception)(socket.gethostbyname)(f"{domain}.{zone}").unwrap_or("")

Then, I would freeze the column (') and delete the expression column, so that it gets cached and the whole sheet doesn't get super slow to navigate.

[frosencrantz]

Thanks for sharing @redraw.

You might be able to remove the need for the freeze column if you are willing to add some code to you .visidatarc or create a simple plugin. The shell column only runs the command for a row once. You can look at what Visidata does for the ColumnShell column. It does caching. You can see it here:

https://github.com/saulpw/visidata/blob/develop/visidata/shell.py#L59

[redraw]

Great, it's just that the experience is different, and in this case it's not a column from a shell cmd, but a Python expression.

Without freezing, visidata gets stucked until results are returned, meanwhile while freezing you can navigate rows and missing values are shown empty (Φ). This also happens just after I create the column from the Python expression. It gets stucked until the visible rows are completed.

I'm running the latest version, visidata==2.11, haven't looked at the code yet to debug why it might happen