But aren't you faced with this issue:

```
In [1]: def f1(a='', b='', c=''):
   ...:     print a, b, c
   ...:     
In [2]: f1(a='', b='', c='', d='')
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-2-5d29265aa69d> in <module>()
----> 1 f1(a='', b='', c='', d='')

TypeError: f1() got an unexpected keyword argument 'd'
```