The introduction is almost identical: '[Pylsy/PrettyTable] is a simple Python library designed to make it quick and easy to represent tabular data in visually appealing ASCII tables'
Aha! That must have been the first time I have tried to read Tcl for more than a minute :) Looks like one can prototype fast in this language. Thanks for writing / posting!
Judging by this thread there are a surprising number of tools dedicated to this. Typically when I need tabular output I stick the data into a Pandas dataframe and its output format is usually good enough.
This is my choice for tables on Python - https://github.com/Robpol86/terminaltables. The appearance of tables is adequately configurable. The project is also actively maintained unlike some of the others.
This recalls some of the table formatting and exporting magic one can easily achieve with emacs org-mode. http://orgmode.org/guide/Tables.html
And there, if you like, you can include a full set of spreadsheet operations.
csvlook [0] is another great tool that does this for any CSV file. It's part of the very useful csvkit[1] suite of command line utilities for working with CSV files.
Note the variety of formats: 'ascii', but also html, latex & co.