On Sat, Nov 21, 2015 at 1:46 AM, Chris Angelico <ros...@gmail.com> wrote: > On Sat, Nov 21, 2015 at 7:38 PM, Todd <toddr...@gmail.com> wrote: >> Rather than a dedicated syntax, might this be something that could be >> handled by a built-in decorator? >> >> Maybe something like: >> >> @late_binding >> def myfunc(x, y=[]): > > No, it can't; by the time the decorator runs, the expression has > already been evaluated. Without syntax, this can only be done with > gross hacks like lambda functions. > > It could be done thus: > > @late_binding > def myfunc(x, y=lambda: []): > > and then the decorator could wrap the function. I'm not entirely sure > I could implement it reliably, but even leaving that aside, having to > put "lambda:" in front of everything is pretty ugly.
Note that "lambda: []" can also be spelled "list". -- https://mail.python.org/mailman/listinfo/python-list
