[pyar] Problema interesante: el anti-string

[Pablo Ziliani]

Roberto Alsina wrote:
> Dado un string S, crear una funcion f tal que  S1>S2 => f(S1) < f(S2)


o sea, algo así pero donde a[1] sea un caracter razonable, no?

 >>> a = ['papa', 'foo', 'pepe', 'bar', 'python']        
 >>> m = ord(max(''.join(a)))
 >>> b = [(i, ''.join(chr(m - ord(j)) for j in i)) for i in a]
 >>> b
[('papa', '\t\x18\t\x18'), ('foo', '\x13\n\n'), ('pepe', 
'\t\x14\t\x14'), ('bar', '\x17\x18\x07'), ('python', 
'\t\x00\x05\x11\n\x0b')]
 >>> sorted(b, key=lambda x:x[0])
[('bar', '\x17\x18\x07'), ('foo', '\x13\n\n'), ('papa', '\t\x18\t\x18'), 
('pepe', '\t\x14\t\x14'), ('python', '\t\x00\x05\x11\n\x0b')]
 >>> sorted(b, key=lambda x:x[1])
[('python', '\t\x00\x05\x11\n\x0b'), ('pepe', '\t\x14\t\x14'), ('papa', 
'\t\x18\t\x18'), ('foo', '\x13\n\n'), ('bar', '\x17\x18\x07')]