That won't work with at least some builtins written in C, and maybe
extension modules. I just checked 3.9 and str.count, and
inspect.signature fails with ValueError: no signature found for builtin
<method 'count' of 'str' objects>.
I don't know if Argument Clinic (AC) would improve this, or maybe it's
outside of what AC can help with.
I've often wanted to call functions, including builtins, and say "just
use the default", so I can see the need for a more reliable way of
finding the defaults.
Eric
On 10/26/2020 5:25 AM, [email protected] wrote:
I wouldn't call it tricky, it's actually quite straightforward:
import inspect
def extract_default(function, parameter):
sig = inspect.signature(function)
param = sig.parameters[parameter]
return param.default
def do_something(count=5):
print(count)
def do_something_twice(count=None):
if count is None:
count = extract_default(do_something, "count")
do_something(count)
do_something(count)
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