hi, I'm not sure why this hasn't come up yet, but this seems to beg for list comprehensions, if not generator expressions. All of the following run in under 2 seconds on my old laptop:
>>> alph = 'abcdefghijklmnopqrstuvwxyz' >>> len([''.join((a,b,c,d)) for a in alph for b in alph for c in alph for d in >>> alph]) 456976 >>> len([''.join((a,b,c,d)) for a in alph for b in alph for c in alph for d in >>> alph ... if (a>=b and b>=c and c>=d)]) 23751 >>> len([''.join((a,b,c,d)) for a in alph for b in alph for c in alph for d in >>> alph ... if (a!=b and b!=c and c!=d and d!=a and b!=d and a!=c)]) 358800 >>> len([''.join((a,b,c,d)) for a in alph for b in alph for c in alph for d in >>> alph ... if (a>b and b>c and c>d)]) 14950 cheers, Jess -- http://mail.python.org/mailman/listinfo/python-list
