1"""Use C-extensions from asecext. 

2 

3This module defines a decorator that can be used to replace pure Python 

4functions with faster C-implementations from the ase_ext module. 

5""" 

6 

7import functools 

8 

9try: 

10 import ase_ext 

11except ImportError: 

12 ase_ext = None 

13 

14 

15def cextension(func): 

16 if ase_ext is None: 

17 return func 

18 cfunc = getattr(ase_ext, func.__name__, None) 

19 if cfunc is None: 

20 return func 

21 functools.update_wrapper(cfunc, func) 

22 cfunc.__pure_python_function__ = func 

23 return cfunc