# Functools.partial extension to support specific positional arguments

**URL:** <https://discuss.python.org/t/functools-partial-extension-to-support-specific-positional-arguments/19163>\
**Category:** Ideas\
**Created:** [September 16, 2022, 10:34am UTC](https://discuss.python.org/t/functools-partial-extension-to-support-specific-positional-arguments/19163 "2022-09-16T10:34:52Z")\
**Posts on this page:** 1\
**Showing post:** 9

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**Author:** ![rhettinger](https://sea2.discourse-cdn.com/flex002/user_avatar/discuss.python.org/rhettinger/32/1129_2.png) [@rhettinger](https://discuss.python.org/u/rhettinger)\
**Post date:** [September 17, 2022, 9:19pm UTC](https://discuss.python.org/t/functools-partial-extension-to-support-specific-positional-arguments/19163/9 "2022-09-17T21:19:18Z")

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> But to me it seems to be an idea worth considering to add to python.

I disagree.

It’s true that when people learn about `partial()`, it is common to wonder about breaking out its left-to-right rule. However, when experimenters go down this path, they create a new problem – how do you specify which argument positions get the frozen values? There are many creative solutions; however, they are all worse than just using a `lambda` or `def` to write a wrapper function.

The best attempt I’ve seen is the [better\_partial](https://github.com/chrisgrimm/better_partial) project. It has many features, but the core syntax is `g = partial(f)(10, _, 20, _, 30)` to create the equivalent of `g = lambda b, d: f(10, b, 20, d, 30)`.

Every variant I’ve seen is more complex, less speedy, and harder to debug than a simple `def` or `lambda`. Every variant required something extra to learn and remember, unlike `def` or `lambda` which are Python basics.

In addition, the use case is questionable. It is mostly an anti-pattern to create functions that take many positional arguments:

```auto
>>> twitter_search('#python', 20, False, True, {'US', 'UK', 'FR'}, 'json')

```

Another problem is that all the proposals I’ve seen restrict you from changing the argument order, from specifying default values, from writing type annotations, and from writing a better docstring. The proposals preclude options that are easily possible with `def` and `lambda`, for example:

```auto
def python_search(retweets: bool, num_tweets: int, format: str='json'):
    'Search #python hash tag in the US, France, and UK for tweets without unicode.'
    return twitter_search('#python', num_tweets, False, retweets, {'US', 'UK', 'FR'}, format)

```

IMO, a more advanced `partial()` is an attractive nuisance that steers people away from the better and obvious solution that we already have today.

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