how to import __future__ for keyword-only argument of python 3.0?

Question

The following code in python2.6 throws syntax error

>>> def f(a,*args,c):
  File \"\", line 1
    def f(a,*args,c):
                  ^         


        

Answer 1

Another way to emulate keyword-only-arguments is:

def f(a, *args, **kwds):
    b = kwds.get('b', 42) # 42 being the default for b

if you wan't to make sure that no unsolicited arguments are passed you can use pop instead:

def f(a, *args, **kwds):
    b = kwds.pop('b', 42)

    assert not kwds # after we've popped all keywords arguments kwds should be empty