[Python-Dev] What does a double coding cookie mean?

Serhiy Storchaka storchaka at gmail.com
Wed Mar 16 03:09:08 EDT 2016

On 16.03.16 08:34, Glenn Linderman wrote:
>  From the PEP 263:
>> More precisely, the first or second line must match the regular
>>     expression "coding[:=]\s*([-\w.]+)". The first group of this
>>     expression is then interpreted as encoding name. If the encoding
>>     is unknown to Python, an error is raised during compilation. There
>>     must not be any Python statement on the line that contains the
>>     encoding declaration.
> Clearly the regular expression would only match the first of multiple
> cookies on the same line, so the first one should always win... but
> there should only be one, from the first PEP quote "a magic comment".

"The first group of this expression" means the first regular expression 
group. Only the part between parenthesis "([-\w.]+)" is interpreted as 
encoding name, not all expression.

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