David C. Ullrich wrote: > In article <tm6dnzxrviq0qfbunz2dnuvz_rmdn...@pdx.net>, > Scott David Daniels <scott.dani...@acm.org> wrote: > >> Mensanator wrote: >> > On Mar 26, 11:42 am, "andrew cooke" <and...@acooke.org> wrote: >> >> ... >> >> that's cute, but if you show them 2.6 or 3 it's even cuter: >> >> >> >>>>> from operator import add >> >>>>> class Vector(list): >> >> ... def __add__(self, other): >> >> ... return map(add, self, other) >> >> ...>>> x = Vector([1,2]) >> >>>>> x+x >> >> [2, 4] >> > >> > What would you have to do to make this work? >> > >> >>>> x+x+x # expecting [3,6] >> > [2, 4, 1, 2] >> > >> >> class Vector(list): >> def __add__(self, other): >> return type(self)(x + y for x, y in zip(self, other)) > > Question: I would have thought it would be > > return type(self)([x + y for x, y in zip(self, other)]) > > What's this thing that looks like a list comprehension but isn't?
it's a generator expression. http://docs.python.org/3.0/reference/expressions.html#index-3735 andrew -- http://mail.python.org/mailman/listinfo/python-list
