I used "..." in my lib to do that : from funcoperators import bracket @bracket def foo(x, y): print(x, y) partialized = foo[..., 10] partialized(5) https://pypi.org/project/funcoperators/ Le dim. 23 juin 2019 à 21:34, James Lu a écrit :

Make $ a valid identifier and a singleton.

$ is a useful placeholder in [].

Possible function partial syntax:

def foo(x, y):

print(x, y)

partialized = foo[$, 10]

partialized(5)

# => 5 10

_______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-leave@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/V7ZCLM... Code of Conduct: http://python.org/psf/codeofconduct/

On Jun 23, 2019, at 17:01, Steven D'Aprano wrote:

...

On Sun, Jun 23, 2019 at 03:22:37PM -0400, James Lu wrote: Make $ a valid identifier and a singleton.

$ is a useful placeholder in [].

Possible function partial syntax:

def foo(x, y): print(x, y)

partialized = foo[$, 10]

I don't think that creating partial functions is important enough to:

1. make partial functions a built-in language feature; 2. using syntax (square brackets); 3. and require a new built-in singleton.

I think that functools.partial is missing two features:

- the ability to close over positional parameters from the right, rather than the left;

- the ability to skip parameters.

The first could be solved with a "rpartial" function, and the second by using ellipsis ... as a placeholder, or a named constant in the functools module.

I’m pretty sure there are multiple improved-partial projects on PyPI. Maybe just picking out one and adding a link to it from the functools docs is sufficient?