Message222857
The docstring is correct, as this is how wraps is implemented (see Lib/functools.py#l73).
partial(update_wrapper, wrapped=wrapped, assigned=assigned, updated=updated) will return a partial version of update_wrapper() where only the wrapper argument is missing. The missing argument is the function decorated with wraps().
For example, this code:
def my_decorator(f):
@wraps(f)
def wrapper(*args, **kwds):
return f(*args, **kwds)
return wrapper
is equivalent to:
def my_decorator(f):
def wrapper(*args, **kwds):
return f(*args, **kwds)
wrapper = wraps(f)(wrapper)
return wrapper
Here wraps(f) creates a partial version of update_wrapper, with only the "wrapped" argument (i.e. f) set. When the partial object returned by wrap(f) gets called, the missing "wrapper" argument is received, thus making wraps(f)(wrapper) equivalent to:
def my_decorator(f):
def wrapper(*args, **kwds):
return f(*args, **kwds)
wrapper = update_wrapper(wrapper, f)
return wrapper
That said, I agree that the sentence you quoted is not too clear/intuitive, but the following example is quite clear, so I'm not sure it's worth to removing/rephrasing the first part.
Maybe it could say something like "This is a convenience function for invoking update_wrapper() (by using partial(update_wrapper, wrapped=wrapped, assigned=assigned, updated=updated)) as a function decorator when defining a wrapper function." instead? |
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Date |
User |
Action |
Args |
2014-07-12 17:20:50 | ezio.melotti | set | recipients:
+ ezio.melotti, rhettinger, terry.reedy, r.david.murray, docs@python, Dustin.Oprea |
2014-07-12 17:20:50 | ezio.melotti | set | messageid: <1405185650.49.0.202542022626.issue21928@psf.upfronthosting.co.za> |
2014-07-12 17:20:50 | ezio.melotti | link | issue21928 messages |
2014-07-12 17:20:49 | ezio.melotti | create | |
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