Astropy Table, formatting of a column with very long text

Description

With astropy.table.Table object, using column.info.format for a str column with long text does not work as expected.

Expected behavior

I would expect it to crop the text. Or, ideally, to split it into lines with no more than the format length.

Actual behavior

For str columns with less symbols than the format length it works correctly, for columns with more symbols than the format length it does nothing.

Steps to Reproduce

Here is a code snippet:

from astropy.table import Table
a = 1
b = 'yes'
c = 'My very long description of this parameter. You have to make sure it is long enough and then try with astropy.table.Table format'

t = Table(names=['a','b','c'],dtype=('int','str','str'))
t.add_row([a,b,c])
t.pprint()
t['b'].info.format='10s'
t['c'].info.format='10s'
t.pprint()

Note that print (t) reports column b as str3 after the format change and not str10. Not sure if this is expected behaviour.

System Details

macOS-10.15.6-x86_64-i386-64bit
Python 3.8.5 (default, Sep  4 2020, 02:22:02) 
[Clang 10.0.0 ]
Numpy 1.19.2
astropy 4.1
Scipy 1.5.0
Matplotlib 3.3.2

[taldcroft]

Sorry for being sloppy. The generic “it always works” form is .info.format. The shorthand .format only works for Column objects, and that syntax should be avoided in examples to avoid this exact confusion! My bad.

[mhvk]

.info.format works also for Quantity in QTable (and for Time, SkyCoord, etc.). For Column, it just sets .format.