pre and post condition wrappers

gistfile1.py

   42 def pre(f, preds):
   43 
   44     @wraps(f)
   45     def inner(*args, **kwargs):
   46         for pred in preds:
   47             assert pred(*args, **kwargs)
   48         return f(*args, **kwargs)
   49 
   50     return inner
   51 
   52 
   53 def post(f, preds):
   54 
   55     @wraps(f)
   56     def inner(*args, **kwargs):
   57         res = f(*args, **kwargs)
   58         for pred in preds:
   59             assert pred(res)
   60         return res
   61 
   62     return inner