# Should \`None\` defaults for optional arguments be discouraged?

**URL:** <https://discuss.python.org/t/should-none-defaults-for-optional-arguments-be-discouraged/23554>\
**Category:** Core Development\
**Created:** [February 5, 2023, 1:04pm UTC](https://discuss.python.org/t/should-none-defaults-for-optional-arguments-be-discouraged/23554 "2023-02-05T13:04:56Z")\
**Posts on this page:** 1\
**Showing post:** 11

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**Author:** ![guido](https://sea2.discourse-cdn.com/flex002/user_avatar/discuss.python.org/guido/32/21_2.png) [@guido](https://discuss.python.org/u/guido)\
**Post date:** [February 5, 2023, 7:51pm UTC](https://discuss.python.org/t/should-none-defaults-for-optional-arguments-be-discouraged/23554/11 "2023-02-05T19:51:09Z")

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Contrary to most reactions, I find it natural and desirable to accept `None` as an alternative to omit an optional parameter in a wide variety of APIs. Not because I like to read or write `log(2.3, None)` but because I like to be able to define a simple wrapper, e.g.

```plaintext
def my_log(x, base=None):
    # <extra stuff here>
    return math.log(x, base)

```

This allows both `my_log(x)` and `my_log(x, base)` to be called, and `my_log()` doesn’t have to hard-code knowledge about the default base. While it is possible to write a wrapper that accepts an optional extra argument and passes that on only when present, it is uglier and harder to read, e.g.

```plaintext
def my_log(x, *args):
    assert len(args) in (0, 1))
    # <extra stuff here>
    return math.log(x, *args)

```

This is slower too (even if you take out the `assert`) because handling `*args` takes a slower path in the interpreter. And why should you have to do it this way?

( **EDIT:** The version with `*args` also makes it more awkward to access `base` in the wrapper in case the “extra stuff” wants to intercept a certain base.)

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