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eevee · 2014-05-27 06:41:08+00:00

Don't try to fake anonymous functions in Python. Use its strengths: decorators, generators, etc.

Anonymous functions work well (err, passably) in JavaScript and Perl. They don't really work in Python, and of course you'll just run into pain if you try to force them to.

Perhaps also make some noise about this PEP: http://legacy.python.org/dev/peps/pep-0403/

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HerrMonnezza | karma 1581 | avg karma 7.64 · | 2022-01-08 15:10:07

The Python package lambdex [1] provides a way to write multi-line anonymous functions in Python, with a syntax that's close enough to the "normal" Python.

[1]: https://pythonrepo.com/repo/hsfzxjy-lambdex

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icebraining | karma 48925 | avg karma 2.14 · | 2015-02-14 17:13:13

Nice article, though I already understood the matter. Thanks for the link to PEP 463[1], though; I can see it cleaning up some of our code. Do you know if there have been any developments into implementing it?

[1] http://legacy.python.org/dev/peps/pep-0463/

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sunqiang | karma 20 | avg karma 1.0 · | 2011-03-06 09:33:05+00:00

yeah, http://www.python.org/dev/peps/pep-0374/

est | karma 8357 | avg karma 2.2 · | 2018-07-03 09:03:22

It's a controversial PEP https://www.python.org/dev/peps/pep-0572/ which allows you to write Python like this:

    def foo():
        if n := randint(0, 3):
            return n ** 2
        return 1337


    [(x, y, x/y) for x in input_data if (y := f(x)) > 0]

bcl | karma 5434 | avg karma 6.08 · | 2013-10-13 16:15:34

This is also helpful - http://docs.python.org/2.7/howto/functional.html

vsmhn | karma 115 | avg karma 5.75 · | 2019-08-08 11:40:11+00:00

Precisely my thought :).

Also, what about the builtin array module? https://docs.python.org/3.7/library/array.html

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devgutt | karma 304 | avg karma 1.11 · | 2013-07-16 15:19:04

http://docs.python.org/2/library/functions.html#eval

e12e | karma 13838 | avg karma 1.49 · | 2014-03-18 02:14:08+00:00

Indeed, AFAIK this is the relevant pep:

http://legacy.python.org/dev/peps/pep-0450/

Note especially the pitfalls highlighted around naive diy solutions (not sure if this is actually taken care of in the module, but I hope so! :-).

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Cald | karma 12 | avg karma 2.0 · | 2009-08-28 14:09:20

I think the nonlocal keyword would make your second example work as you expect (but I can't test it as I don't have Python 3.0 installed here).

See http://www.python.org/dev/peps/pep-3104/

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natrius | karma 8673 | avg karma 3.35 · | 2010-11-07 20:47:26+00:00

Neat, but you should check out PEP 8 at some point. An empty line between a decorator and the decorated function (flask) is confusing, and whitespace in keyword arguments just looks off.

http://www.python.org/dev/peps/pep-0008/

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syassami | karma 218 | avg karma 2.27 · | 2022-07-18 15:39:50

You can go even further now with PEP508 https://peps.python.org/pep-0508/

futureastronaut | karma 342 | avg karma 2.07 · | 2019-03-17 20:18:21

Python's list of built-in functions is fairly small https://docs.python.org/3/library/functions.html#built-in-fu... (but to be clear, I wouldn't ding somebody for forgetting about one of them).

dmytrish | karma 927 | avg karma 2.6 · | 2017-09-14 13:32:37+00:00

This is also a good addition for functional programming in Python:

https://github.com/kachayev/fn.py

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villgax | karma 976 | avg karma 0.98 · | 2020-05-23 13:30:25+00:00

https://www.programiz.com/python-programming/anonymous-funct...

henbruas | karma 18 | avg karma 2.25 · | 2022-06-06 01:44:33

It is indeed a decorator. It's relying on https://peps.python.org/pep-0614/

sadiq | karma 4786 | avg karma 12.06 · | 2011-02-14 23:42:34+00:00

http://docs.python.org/library/functions.html#hash

pacofvf | karma 361 | avg karma 1.87 · | 2014-06-12 22:35:12

https://docs.python.org/2/howto/functional.html

trishankdatadog | karma 137 | avg karma 2.04 · | 2020-09-06 00:04:00+00:00

Yes, please see PEP 458: https://www.python.org/dev/peps/pep-0458/

barosl | karma 695 | avg karma 4.6 · | 2015-06-16 18:46:26+00:00

This is certainly an interesting idea. A quick Google search gave me this toy example: [1][2]

Of course making it work for all cases would be very hard due to the excessive dynamism of Python, but for simple arithmetic operations it could be made to work fairly well.

[1] http://tomforb.es/automatically-inline-python-function-calls

[2] https://github.com/orf/inliner

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