BUG: lib: Fix a problem with vectorize with default parameters.

When `otypes` is given to `vectorize` and then the instance is
called, it creates a ufunc by calling numpy.core.umath.frompyfunc.
The number of arguments given to this ufunc is set to the number
of arguments in the call of the vectorize instance.  This ufunc
is cached, so frompyfunc does not have to be called on the next
call. The problem is that, if the function being wrapped has
parameters with default values, the number of arguments passed
to the vectorize instance can change, and when that happens, a
new ufunc must be created by calling frompyfunc with the correct
number of arguments.

This commit changes the cache of the ufunc from a simple attribute
that holds the most recent ufunc to a dictionary whose keys are
the number of arguments in the call.  The cache is only used when
the vectorized function is called with only positional arguments
and there are no excluded arguments.  If keywords are used, the
number of arguments is no longer sufficient to uniquely identify a
previously created ufunc.

Closes gh-16120.

0 files changed, 0 insertions, 0 deletions