This is the = command that adds a new column based on a Python expression you provide. You can reference the cells in the current row based on the column name.
It is also possible to create a column based on the output of a shell command.
VisiData is row based, not cell based, so you cannot create expressions that reference data across rows.
I am seeing this issue on a Mac with ghostty but not with wezterm, from the same binary. Ghostty shows some correct characters and some diamond-question marks, and a line usually contains one or the other. The ghostty inspector shows the diamonds are not the blocks.
Thank you for doing this, this is fun. Also, I love all the nostalgic comments.
I'm surprised no one has mentioned Robert Tinney the artist who illustrated many of the covers. His work is pretty amazing, and seemed to capture all sorts of interesting ideas.
I met him once at a computer show. I was in too much in awe that I didn't really talk with him, but was able to give him some praise for his artwork. Also, I bought one of the t-shirts with his artwork.
One my favorite tools is Visidata (https://www.visidata.org/). It is great for viewing and working with data in the terminal. It is useful if you need to quickly explore data and change some data.
VisiData makes it possible to view a lot of data such as CSV, JSON, databases, etc. All the supported formats are listed in https://www.visidata.org/docs/formats/
One of my favorite tools. However, I don’t think that Visidata is a spreadsheet, even though it looks like one and is named after one. It is more spreadsheet adjacent. It is focused on row-based and column-based operations. It doesn’t support arbitrary inter-cell operation(s), like you get in Excel-like spreadsheets. It is great for “Tidy Data’, where each row represents a coherent set of information about an object or observation. This is very much like Awk, or other pipeline tools which are also line/row oriented.
This works great with terminals that can handle ligatures. I've used it with Kitty and recently tried it with Ghostty. The author shows several different examples using the fonts to make groups of 3 digits within larger numbers easier to read by adding underlines, grouping numbers closer, bolding numbers, and adding virtual commas. I say the commas are virtual since they are only visible by the font rendering, if you were to copy and paste the numbers the commas would not be included.
The author provides a font patching tool, however mentions that it does not preserve existing ligatures.
This font can be useful when looking at large numbers. I've used it with successfully with Visidata in sheets with large numbers.
If you are interested in this subject, Carl Zimmer wrote a great book that has all sorts of examples of parasites that control their host: "Parasite Rex: Inside the Bizarre World of Nature's Most Dangerous Creatures"
Atul Gawande is a surgeon by training and an exceptional writer. He has authored several other wonderful books, known for his ability to explain complex topics in an accessible way. His website (http://atulgawande.com) features his books, articles, and papers along with information about his other endeavors.
There was a lot of effort to add many more help guides that provide context-sensitive help where you need it. The main complaint I’ve read from people is that VisiData is too complex. The last few releases have attempted to address these concerns with the guides, the command palette, and the menu system. I think these all provide help when it is needed.
Though I think it is possible to get a lot done with VisiData only knowing a handful of commands/operations.
It is also possible to create a column based on the output of a shell command.
VisiData is row based, not cell based, so you cannot create expressions that reference data across rows.