[Python-ideas] Deprecating rarely used str methods

[Serhiy Storchaka]

The str class have some very rarely used methods. When was the last time 
you used swapcase() (not counting the time of apprenticeship)? These 
methods take place in a source code, documentation and a memory of 
developers. Due to the large number of methods, some of the really 
necessary methods can be neglected. I propose to deprecate rarely used 
methods (especially that for most of them there is another, more obvious 
way) and remove them in 4.0.

s.ljust(width) == '{:<{}}'.format(s, width) == '%-*s' % (width, s)
s.ljust(width, fillchar) == '{:{}<{}}'.format(s, fillchar, width)
s.rjust(width) == '{:>{}}'.format(s, width) == '%*s' % (width, s)
s.rjust(width, fillchar) == '{:{}>{}}'.format(s, fillchar, width)
s.center(width) == '{:^{}}'.format(s, width)
s.center(width, fillchar) == '{:{}^{}}'.format(s, fillchar, width)

str(n).zfill(width) == '{:0={}}'.format(n, width) == '%0*.f' % (width,n)

str.swapcase() is just not needed.

str.expandtabs([tabsize]) is rarely used and can be moved to the 
textwrap module.