Thank you Antoine for your review.

But first variant of the patch doesn't affect an example at the top of this issue, it doesn't change string formatting. The second variant makes string formatting use all free space at the right. With the patch:

>>> import pprint
>>> print('='*80)  # a rule
================================================================================
>>> pprint.pprint([' '.join(str(i) for i in range(30))]*2)
['0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 '
 '29',
 '0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 '
 '29']
>>> pprint.pprint([[[[[[[[[[[[' '.join(str(i) for i in range(30))]]]]]]]]]]]]*2)
[[[[[[[[[[[['0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 '
            '25 26 27 28 29']]]]]]]]]]],
 [[[[[[[[[[['0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 '
            '25 26 27 28 29']]]]]]]]]]]]

Could you please make a review of new patch?