Following r81811 (and issue8925), perhaps we should start using e.g. PyUnicode, PyBytes, PyLong, etc. in the C API docs to more closely follow the C API rather than use the type names you see at the Python level.

Big patch:
 - replace Python types by C Python types (eg. str => PyUnicodeObject* and None => Py_None)
 - fix "w" / "w*" / "w#" doc: similar to "y" / "y*" / "y#" (and not "s" / "s*" / "s#")
 - add quotes to the formats, eg. s => "s"
 - use :ctype: to add links to some terms (eg. Py_BEGIN_ALLOW_THREADS) and use a fixed width font
 - replace "the default encoding" by "'utf-8' encoding"
 - replace true by 1, and false by 0 (C API of Python doesn't use stdbool.h but classic int)
 - use a list for the two modes of "es#"
 - Py_BuildValue(), "s" and "s#" formats: specify that the Python object is a str

1 and 0 were formatted with ``1`` and ``0``. I don't understand why, so I removed the italic style.

Sorry for the length of the patch, but it was easy to work on only one aspect.

Other changes of the patch:
 - "u#": remove "Non-Unicode objects are handled by interpreting their read-buffer pointer ...", it's no more true
 - "es", "es#": remove "... and objects convertible to Unicode into a character buffer", it's no more true
 - Py_BuildValue(), "K" and "L" formats: specify the name of the C type on Windows (_int64 / unsigned _int64) as done for PyArg_Parse*() long long types

If the patch is too long, I can try to split it into smaller parts.

STINNER Victor wrote:
> 
> STINNER Victor <victor.stinner@haypocalc.com> added the comment:
> 
> Big patch:
>  - replace Python types by C Python types (eg. str => PyUnicodeObject* and None => Py_None)

I was thinking of e.g. "PyUnicode", not "PyUnicodeObject*".

>  - add quotes to the formats, eg. s => "s"

Why do you put the parser codes in double quotes ?

>  - use :ctype: to add links to some terms (eg. Py_BEGIN_ALLOW_THREADS) and use a fixed width font
>  - replace "the default encoding" by "'utf-8' encoding"
>  - replace true by 1, and false by 0 (C API of Python doesn't use stdbool.h but classic int)

That's not necessarily correct: true in C means non-zero. Only
false equates to 0. You can however, make that change if the
function actually does always return 1.

In general, most C functions in Python use these integer
return values:

 1  - success
 0  - no success
 -1 - error

Some of them also return a positive integer >1 for success or
a negative integer <-1 for error, but those are exceptions.

Le mercredi 09 juin 2010 11:06:25, vous avez écrit :
> >  - replace Python types by C Python types (eg. str => PyUnicodeObject*
> >  and None => Py_None)
> 
> I was thinking of e.g. "PyUnicode", not "PyUnicodeObject*".

I don't know PyUnicode, only "unicode" (Python type) or "PyUnicodeObject*" (C 
Python type). :ctype:`PyUnicodeObject*` creates a link in the HTML 
documentation.

> >  - add quotes to the formats, eg. s => "s"
> 
> Why do you put the parser codes in double quotes ?

It's easier to search a format: try to search s or b format in the current 
documentation, you will see :-)

I think that it's also more readable and closer to the "real" source code (eg. 
a call to PyArg_ParseTuple() uses quotes).

> >  - replace true by 1, and false by 0 (C API of Python doesn't use
> >  stdbool.h but classic int)
> 
> That's not necessarily correct: true in C means non-zero. Only
> false equates to 0. You can however, make that change if the
> function actually does always return 1.

There are only 2 possible results: 0 or 1.

STINNER Victor wrote:
> 
> STINNER Victor <victor.stinner@haypocalc.com> added the comment:
> 
> Le mercredi 09 juin 2010 11:06:25, vous avez écrit :
>>>  - replace Python types by C Python types (eg. str => PyUnicodeObject*
>>>  and None => Py_None)
>>
>> I was thinking of e.g. "PyUnicode", not "PyUnicodeObject*".
> 
> I don't know PyUnicode, only "unicode" (Python type) or "PyUnicodeObject*" (C 
> Python type). :ctype:`PyUnicodeObject*` creates a link in the HTML 
> documentation.

The "PyUnicode" style is just an abbreviated version of the longer
"PyUnicodeObject", that we sometimes use, since writing "Pass
a PyUnicodeObject object to this function" looks a bit silly.

I don't have a strong opinion about this, though. The longer
version is fine as well.

>>>  - add quotes to the formats, eg. s => "s"
>>
>> Why do you put the parser codes in double quotes ?
> 
> It's easier to search a format: try to search s or b format in the current 
> documentation, you will see :-)
> 
> I think that it's also more readable and closer to the "real" source code (eg. 
> a call to PyArg_ParseTuple() uses quotes).

It could lead developers into thinking that they have to use
those quotes in their code.

Perhaps you should add a note about this typographic addition
to docs.

>>>  - replace true by 1, and false by 0 (C API of Python doesn't use
>>>  stdbool.h but classic int)
>>
>> That's not necessarily correct: true in C means non-zero. Only
>> false equates to 0. You can however, make that change if the
>> function actually does always return 1.
> 
> There are only 2 possible results: 0 or 1.

I wouldn't count on this. It may be the case now, but it's both
hard to check by reading the code and knowing that only 1 can
be returned doesn't buy a developer much.

In fact, this has
bitten us before with the cmp() function: users starting writing
code like this because we documented the return codes as -1, 0, 1:

a = b + z * cmp(x, y)

Please use "non-zero" instead.

> 1 and 0 were formatted with ``1`` and ``0``. I don't understand why,
> so I removed the italic style.

This reST construct marks up code. Please revert this change. :)

FWIW, I prefer PyLongObject* over PyLong.  (Though I'm sure I'm guilty of writing PyLong in comments.)

I commited a first part of the patch: r81923 (3.2), r81924 (3.1).

"PyUnicodeObject*" is not the best choice for the description of the function, and I don't really like "PyUnicode". Can't we use C types in the function prototype and Python types in the description?

Example:
-------
s (PyUnicodeObject* or None) [char *]
Convert a null-terminated C string to a Python unicode object using 'utf-8' encoding. If the C string pointer is NULL, None is used.
-----
PyUnicodeObject will be a link to the C type, and unicode a link to the  Python type.

r82084 (in 3.2 and r82085 in 3.1) fixes some of the reported issues.

Shouldn’t “inside a :ctype:`Py_BEGIN_ALLOW_THREADS` block” rather use “:cmacro:”?

> Shouldn’t “inside a :ctype:`Py_BEGIN_ALLOW_THREADS` block” rather use “:cmacro:”?

Same remark on IRC: "Taggnostr> haypo, in r82084: "Add :ctype: to Py_BEGIN_ALLOW_THREADS and int", maybe :cfunc: (or :cmacro:)?"

I don't know :cmacro:. I will fix it in my next patch.

+1 on using the full name, PyUnicodeObject

The shorthand "PyUnicode" is too easy to confuse with Py_UNICODE (an actual type).

To avoid the strange-looking “a PyUnicodeObject object”, one can write “an instance of PyUnicodeObject”.

Victor, have you kept the ```` around 0 and 1?

> To avoid the strange-looking “a PyUnicodeObject object”, one can write
> “an instance of PyUnicodeObject”.

Or simply "a PyUnicodeObject".