Re: [Python-Dev] Issue #26204: compiler now emits a SyntaxWarning on constant statement

On 2016-02-08 23:21, Chris Barker wrote:
> On Mon, Feb 8, 2016 at 1:51 PM, Victor Stinner <vict...@gmail.com> <mailto:vict...@gmail.com>> wrote:>>     I didn't know. I just checked. It's assert used with a non-empty tuple:>>      >>> assert ("tuple",)>>> which is more interesting with a tuple without the parentheses:>> t = In [*4*]: t = True,>> In [*5*]: t>> Out[*5*]: (True,)>> works fine, but not if you use an assert:>> In [*7*]: assert True,>>    File "<ipython-input-7-38940c80755c>", line 1>>      assert True,>>                  ^>> SyntaxError:invalid syntax>> I actually like the Warning with the note about the problem better:>>     <stdin>:1: SyntaxWarning: assertion is always true, perhaps remove>     parentheses?>>> And, of course, more relevant with something Falsey in the tuple:>> In [*14*]: assert (False,)>> <ipython-input-14-05f425f558c4>:1: SyntaxWarning: assertion is always> true, perhaps remove parentheses?>>    assert (False,)>> But I am curious why you get a different error without the parens?>
Try:

     help('assert')

You'll see that in "assert (True,)", the tuple (an object) is the first 
condition (and probably a mistake), whereas in "assert True,", the True 
is the condition and the second expression (after the comma) is missing.
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