IPython.utils.columnize sometime wrong...

[Carreau]

In [1]: import IPython.utils.text as ut
   ...: len(ut.columnize(['x'*40,'x'*40],displaywidth=80).split('\n')[0])
Out[1]: 82 # should be < 80

two 40 letters words separated by 2 char could not enter on a 80 char line.
should be 2 times 40(+separator size maybe)

[Carreau]

cf http://hg.python.org/cpython/file/2.7/Lib/cmd.py#l349
for a working implementation.

[takluyver]

Do we need anything over and above what's in cmd, or can we just call that?

[Carreau]

I'll need a little more abstract methods for #1851 that return a nested list.

As they are computated, it can also return the number of row, number of columns, and width of each column.
Then having the current columnize is just 2 lines of map/join, but I have the intermediate step that allow me to navigate the list up down, and easily insert the tag to hilight one particular item.

I was thinking of an abstart methods that takes a list of length, and return a nested list of array to have something really reusable.