Use inspect.signature() instead of inspect.getfullargspec() #1164
Description
Currently, the implementation of Memory.cache() implements the ignore option using inspect.getfullargspec(). However, this function does not handle decorated functions correctly; inspect.signature(), on the other hand, does. Observe:
from functools import wraps
import inspect
def decorate(f):
@wraps(f)
def wrapped(*args, **kwargs):
return f(*args, **kwargs)
return wrapped
@decorate
def foo(arg, extra=None):
return arg
print(inspect.signature(foo))
print(inspect.getfullargspec(foo))This prints out:
(arg, extra=None)
FullArgSpec(args=[], varargs='args', varkw='kwargs', defaults=None, kwonlyargs=[], kwonlydefaults=None, annotations={})
Note that signature() reports the signature of the original foo, while getfullargspec() reports the signature of wrapped.
As a consequence of this, using the ignore option on a Memory-cached function with an intervening decorator does not work. Example:
from functools import wraps
import inspect
from joblib import Memory
mem = Memory("cache", verbose=0)
def decorate(f):
@wraps(f)
def wrapped(*args, **kwargs):
return f(*args, **kwargs)
return wrapped
@mem.cache(ignore=["extra"])
@decorate
def foo(arg, extra=None):
return arg
foo(1)This fails with the error ValueError: Ignore list: argument 'extra' is not defined for function foo(*args, **kwargs).