Re: RegExp - please help me!

[Lele Gaifax]

szykc...@gmail.com writes:

> Please help me with this regexp or tell me that I neeed do this in other way.

I think that using regexps to parse those structures is fragile and difficult
to get right[0], as there are lots of corner cases (comments, complex types,
...).

I'd suggest using a tool designed to do that, for example pycparser[1], that
provides the required infrastructure to parse C units into an AST: from there
you can easily extract interesting pieces and write out in whatever format you
need.

As an example, I used it to extract[2] enums and defines from PostgreSQL C
headers[3] and rewrite them as Python definitions[4].

Good luck,
ciao, lele.

[0] http://regex.info/blog/2006-09-15/247
[1] https://github.com/eliben/pycparser
[2] https://github.com/lelit/pg_query/blob/master/tools/extract_enums.py
[3] 
https://github.com/lfittl/libpg_query/blob/43ce2e8cdf54e4e1e8b0352e37adbd72e568e100/src/postgres/include/nodes/parsenodes.h
[4] https://github.com/lelit/pg_query/blob/master/pg_query/enums/parsenodes.py
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nickname: Lele Gaifax | Quando vivrò di quello che ho pensato ieri
real: Emanuele Gaifas | comincerò ad aver paura di chi mi copia.
l...@metapensiero.it  | -- Fortunato Depero, 1929.

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Default annotations for variables

[Kirill Balunov]

Will there be any implications (or is it possible) if all variables will
have an attribute *something like* `__type__` which by default will be
initialized to *something like* `AnyType`. So in the case `x = 12` will be
equivalent to `x: AnyType = 12`.

x: int
x = 12
x.__type__ # int

a, b = 11, 12
a.__type__  # AnyType
b.__type__  # AnyType

And also in this case:

class Dummy:
a: int
b: float
c = []

Dummy.__annotations__  # will be {'a': int, 'b': float, 'c': AnyType}


While I ask purely out of curiosity, I think this is not an off-topic for
python-list.

With kind regards, -gdg
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Re: Default annotations for variables

[Chris Angelico]

On Wed, Dec 27, 2017 at 9:41 PM, Kirill Balunov  wrote:
> Will there be any implications (or is it possible) if all variables will
> have an attribute *something like* `__type__` which by default will be
> initialized to *something like* `AnyType`. So in the case `x = 12` will be
> equivalent to `x: AnyType = 12`.
>
> x: int
> x = 12
> x.__type__ # int
>
> a, b = 11, 12
> a.__type__  # AnyType
> b.__type__  # AnyType

This won't work. When you say "a.__type__", it means "take the *value*
referenced by a, and look up its __type__ attribute". So it's
equivalent to writing:

(11).__type__
(12).__type__

To query something about the *variable*, you have to look at its
enclosing namespace. If these are at top level, you'd be looking at
the module-level __annotations__ dictionary. That's also where
x.__type__ would be - it's actually stored in __annotations__["x"].

> And also in this case:
>
> class Dummy:
> a: int
> b: float
> c = []
>
> Dummy.__annotations__  # will be {'a': int, 'b': float, 'c': AnyType}

Now, this situation might be of some interest to the dataclass
discussions. Currently, there's a limitation in that no single source
has information about all three attributes; and that means that the
order ["a", "b", "c"] is actually not stored anywhere. (Annotations
are ordered within themselves; values are ordered within themselves;
but annotations and values are separate.)

There is definitely room to ask the question "can we get default
annotations for any global or class-level name that gets assigned to
without an annotation?". I fully expect that thread to be one of those
gigantic ones, but have fun :)

> While I ask purely out of curiosity, I think this is not an off-topic for
> python-list.

Absolutely, it's not off-topic! Though at some point it might need to
migrate to python-ideas, if there's a proposal to actually change the
language. But there's nothing wrong with asking the question here on
python-list.

ChrisA
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Re: Default annotations for variables

[Kirill Balunov]

2017-12-27 13:54 GMT+03:00 Chris Angelico :

> This won't work. When you say "a.__type__", it means "take the *value*
> referenced by a, and look up its __type__ attribute". So it's
> equivalent to writing:
>
> (11).__type__
> (12).__type__
>

Thank you for clarification, I understand that names don't have attributes
:). But I did not find the right words to describe the idea.


> To query something about the *variable*, you have to look at its
> enclosing namespace. If these are at top level, you'd be looking at
> the module-level __annotations__ dictionary. That's also where
> x.__type__ would be - it's actually stored in __annotations__["x"].
>

Here I was a bit knocked down by the IPython console. Strangely, but the `
__annotations__` is not initialized to a an empty dict when you start it,
while in Python console it is.


> There is definitely room to ask the question "can we get default
> annotations for any global or class-level name that gets assigned to
> without an annotation?". I fully expect that thread to be one of those
> gigantic ones, but have fun :)
>

Yes this is exactly what I was about to ask :)

With kind regards, -gdg
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Re: Default annotations for variables

[Kirill Balunov]

2017-12-27 14:19 GMT+03:00 Kirill Balunov :

> Here I was a bit knocked down by the IPython console. Strangely, but the `
> __annotations__` is not initialized to a an empty dict when you start it,
> while in Python console it is.
>

In addition, there are some imbalance without IPython. Since modules and
classes define namespaces it is strange that:

empty `module` -> has `__annotations__` defined to {}.
empty `class` -> does not have `__annotations__` raises AttributeError.

With kind regards, -gdg
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Re: RegExp - please help me!

[szykcech]

> (?s)struct (.+?)\s*\{\s*(.+?)\s*\};

Thank you Vlastimil Brom for regexp and for explanation!
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PyWin32 installer question

[Skip Montanaro]

I'm fiddling around with Appveyor, trying to build a Windows installer
for SpamBayes. This is complicated by two facts:

1. I don't know squat about Windows.

2. I don't have access to a Windows command line.

Consequently, every new attempt requires a change to appveyor.yml and
a git push command. Rather slow going. My latest Appveyor build number
is 59. Most of the changes were simple fixes for syntax errors.

I got to the point where I (finally!) was able to successfully
download the appropriate pywin32 installer, but executing it just
hangs. I sort of assume it's asking os.devnull for something. Alas, I
couldn't find any sort of command line flags for the installer itself
in the pywin32 code. I've tried

pywin32.exe /h

but that just sits there (ignores that flag?) and

pywin32.exe /?

which produced some inscrutable output.

Is there some way to coax it into giving me some help and exiting?

Thanks,

Skip
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Re: Default annotations for variables

[INADA Naoki]

typing's primary intention is "static" typing with tools like mypy.
Introspection is not primary usage.

Adding such information for every class, module, etc makes
Python slower and fatter.
But I want to make Python more swift and slim.
INADA Naoki  


On Wed, Dec 27, 2017 at 8:39 PM, Kirill Balunov  wrote:
> 2017-12-27 14:19 GMT+03:00 Kirill Balunov :
>
>> Here I was a bit knocked down by the IPython console. Strangely, but the `
>> __annotations__` is not initialized to a an empty dict when you start it,
>> while in Python console it is.
>>
>
> In addition, there are some imbalance without IPython. Since modules and
> classes define namespaces it is strange that:
>
> empty `module` -> has `__annotations__` defined to {}.
> empty `class` -> does not have `__annotations__` raises AttributeError.
>
> With kind regards, -gdg
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> https://mail.python.org/mailman/listinfo/python-list
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[ANN] txaws 0.5.0

[Jean-Paul Calderone]

Hello all,

I'm pleased to announce the release of txAWS 0.5.0.  txAWS is a library for
interacting with Amazon Web Services (AWS) using Twisted.

You can download the release from PyPI .

Since the last release, the following enhancements have been made:

Features
> 
> - txaws.s3.client.S3Client.get_bucket now accepts a ``prefix`` parameter
> for
>   selecting a subset of S3 objects. (#78)
> - txaws.ec2.client.EC2Client now has a ``get_console_output`` method
> binding
>   the ``GetConsoleOutput`` API. (#82)


Thanks to everyone who contributed and to Least Authority TFA GmbH
 for sponsoring my work on this release.

Jean-Paul
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