# Pre-PEP: Unpacking in Comprehensions **URL:** \ **Category:** Ideas\ **Created:** [June 22, 2025, 5:51pm UTC](https://discuss.python.org/t/pre-pep-unpacking-in-comprehensions/96362 "2025-06-22T17:51:34Z")\ **Posts on this page:** 1\ **Showing post:** 7
**Author:** ![blhsing](https://sea2.discourse-cdn.com/flex002/user_avatar/discuss.python.org/blhsing/32/25812_2.png) [@blhsing](https://discuss.python.org/u/blhsing)\ **Post date:** [June 23, 2025, 1:38am UTC](https://discuss.python.org/t/pre-pep-unpacking-in-comprehensions/96362/7 "2025-06-23T01:38:15Z")
I’ve always found it surprising and counter-intuitive that unpacking in comprehensions doesn’t work ever since I learned about generalized unpacking in container literals. That said, I think the PEP needs to address the [concern](https://peps.python.org/pep-0448/#variations) raised by the explanations to why such a feature wasn’t included in PEP-448, specifically that it would cause ambiguity when unpacking in an unbracketed generator expression in a call since argument list already supports unpacking. That is, which one of these is intended? ```python f(*x for x in it) == f((*x for x in it)) ``` or: ```python f(*x for x in it) == f(*(x for x in it)) ``` Original quote from PEP-448: > Unbracketed comprehensions in function calls, such as `f(x for x in it)`, are already valid. These could be extended to: > > ```python > f(*x for x in it) == f((*x for x in it)) > f(**x for x in it) == f({**x for x in it}) > > ``` > > However, it wasn’t clear if this was the best behaviour or if it should unpack into the arguments of the call to `f`. Since this is likely to be confusing and is of only very marginal utility, it is not included in this PEP. Instead, these will throw a `SyntaxError` and comprehensions with explicit brackets should be used instead. --- _[View the full topic](https://discuss.python.org/t/pre-pep-unpacking-in-comprehensions/96362)._