inject.py

import sys

class inject(object):
 def __init__(self, **kwargs):
 self.kwargs = kwargs

 def __call__(self, fn):
 from functools import wraps
 @wraps(fn)
 def wrapped(*args, **kwargs):
 old_trace = sys.gettrace()
 def tracefn(frame, event, arg):
 # define a new tracefn each time, since it needs to
 # call the *current* tracefn if they're in debug mode
 frame.f_locals.update(self.kwargs)
 if old_trace:
 return old_trace(frame, event, arg)
 else:
 return None

 sys.settrace(tracefn)
 try:
 retval = fn(*args, **kwargs)
 finally:
 sys.settrace(old_trace)
 return retval

 return wrapped

 def into(self, fn, *args, **kwargs):
 return self(fn)(*args, **kwargs)