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

The new syntax is discussed in PEP 3102 and it's indeed not valid in Python 2.x.

However you can obtain the keyword arguments from **kwargs manually:

def f(a, *b, **kwargs):
    if 'c' in kwargs:
        pass

The other alternative is to upgrade to Python 3.x.