#permutazioni
from time import clock

def permuta(string):
    string=list(string)
    dim=len(string)
    i=0
    p, mega=[], []
    for x in range(dim):
        p.append(0)
    while i<dim:
        if p[i]<i:
            j=i%2*p[i]
            tmp=string[j]
            string[j]=string[i]
            string[i]=tmp
            mega.append(''.join(string))
            p[i]+=1
            i=1
        else:
            p[i]=0
            i+=1
    return mega

clock()
a=permuta("1234567890")

print "tempo mio permuta: ", clock()