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Created on 2022-03-18 01:17 by bluenix, last changed 2022-04-11 14:59 by admin.
| Pull Requests | |||
|---|---|---|---|
| URL | Status | Linked | Edit |
| PR 32014 | open | gregory.p.smith, 2022-03-20 21:16 | |
| Messages (4) | |||
|---|---|---|---|
| msg415463 - (view) | Author: Bluenix (bluenix) * | Date: 2022-03-18 01:17 | |
Running the code below will produce a SyntaxError with the message: "non-default argument follows default argument".
def test(a=None, b):
return b if a is None else a
The issue is that `a` and `b` aren't *arguments*, rather, they are *parameters*. The error message should be changed to: "non-default parameter follows default parameter".
This change appears simple enough and although it is not something I've found to be troublesome, it will help users to use correct keywords (arguments vs. parameters) when searching on the internet.
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| msg415469 - (view) | Author: Vedran Čačić (veky) * | Date: 2022-03-18 04:48 | |
The problem is more subtle. The thing is, "default parameter" doesn't make sense in this context. Yes, a and b are parameter, but a is not "default parameter" in any sensible way. It is _None_ which is the default argument for parameter a, while parameter b has no default argument. In other words, if the function weren't called with a first argument, the default argument would be used. So, the fix should be a bit more complicated. Maybe, "a parameter without a default follows a parameter with a default"? |
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| msg415526 - (view) | Author: Bluenix (bluenix) * | Date: 2022-03-18 20:37 | |
Yes I agree, that would be the best. |
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| msg415530 - (view) | Author: Terry J. Reedy (terry.reedy) *  |
Date: 2022-03-19 00:45 | |
Current message same in 3.11 and 3.9, but I am not sure about backporting to old parser. However merges a change, if any, can decide. |
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| History | |||
|---|---|---|---|
| Date | User | Action | Args |
| 2022-04-11 14:59:57 | admin | set | github: 91210 |
| 2022-03-20 21:18:26 | gregory.p.smith | set | assignee: gregory.p.smith |
| 2022-03-20 21:16:18 | gregory.p.smith | set | keywords:
+ patch nosy: + gregory.p.smith pull_requests: + pull_request30102 stage: needs patch -> patch review |
| 2022-03-19 00:46:08 | terry.reedy | set | title: "SyntaxError: non-default argument follows default argument" should be "parameter" -> "SyntaxError: non-default argument follows default argument" confuses |
| 2022-03-19 00:45:41 | terry.reedy | set | versions:
+ Python 3.11, - Python 3.7, Python 3.8, Python 3.9 nosy: + pablogsal, terry.reedy messages: + msg415530 type: behavior stage: needs patch |
| 2022-03-18 20:37:06 | bluenix | set | messages: + msg415526 |
| 2022-03-18 04:48:34 | veky | set | nosy:
+ veky messages: + msg415469 |
| 2022-03-18 01:17:42 | bluenix | create | |