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Avoiding boilerplate by using immutable default arguments (vulwsztyn.codeberg.page)
submitted 4 months ago by Vulwsztyn@programming.dev to c/python@programming.dev
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Hi, I recently realised one can use immutable default arguments to avoid a chain of:

def append_to(element, to=None):
    if to is None:
        to = []

at the beginning of each function with default argument for set, list, or dict.

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[-] Narann@jlai.lu 4 points 4 months ago

This is the way you're supposed to write it in Python.

It is something you get used to, yet I think it's sad.

[-] m_f@discuss.online 5 points 4 months ago

You can use mutable default arguments now with a new syntax:

https://peps.python.org/pep-0671/

def bisect_right(a, x, lo=0, hi=>len(a), *, key=None):
def connect(timeout=>default_timeout):
def add_item(item, target=>[]):
def format_time(fmt, time_t=>time.time()):
[-] Vulwsztyn@programming.dev 3 points 4 months ago

This is only a Draft for now though

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this post was submitted on 22 Jul 2025
18 points (100.0% liked)

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