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

Serhiy Storchaka storchaka at gmail.com
Sat Mar 19 11:19:25 EDT 2016

On 16.03.16 08:03, Serhiy Storchaka wrote:
> On 15.03.16 22:30, Guido van Rossum wrote:
>> I came across a file that had two different coding cookies -- one on
>> the first line and one on the second. CPython uses the first, but mypy
>> happens to use the second. I couldn't find anything in the spec or
>> docs ruling out the second interpretation. Does anyone have a
>> suggestion (apart from following CPython)?
>> Reference: https://github.com/python/mypy/issues/1281
> There is similar question. If a file has two different coding cookies on
> the same line, what should win? Currently the last cookie wins, in
> CPython parser, in the tokenize module, in IDLE, and in number of other
> code. I think this is a bug.

I just tested with Emacs, and it looks that when specify different 
codings on two different lines, the first coding wins, but when specify 
different codings on the same line, the last coding wins.

Therefore current CPython behavior can be correct, and the regular 
expression in PEP 263 should be changed to use greedy repetition.

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