mirror of
https://github.com/thelsing/knx.git
synced 2026-02-23 13:50:35 +01:00
update pybind11
This commit is contained in:
@@ -87,7 +87,7 @@ buffer objects (e.g. a NumPy matrix).
|
||||
/* Request a buffer descriptor from Python */
|
||||
py::buffer_info info = b.request();
|
||||
|
||||
/* Some sanity checks ... */
|
||||
/* Some basic validation checks ... */
|
||||
if (info.format != py::format_descriptor<Scalar>::format())
|
||||
throw std::runtime_error("Incompatible format: expected a double array!");
|
||||
|
||||
@@ -150,8 +150,10 @@ NumPy array containing double precision values.
|
||||
|
||||
When it is invoked with a different type (e.g. an integer or a list of
|
||||
integers), the binding code will attempt to cast the input into a NumPy array
|
||||
of the requested type. Note that this feature requires the
|
||||
:file:`pybind11/numpy.h` header to be included.
|
||||
of the requested type. This feature requires the :file:`pybind11/numpy.h`
|
||||
header to be included. Note that :file:`pybind11/numpy.h` does not depend on
|
||||
the NumPy headers, and thus can be used without declaring a build-time
|
||||
dependency on NumPy; NumPy>=1.7.0 is a runtime dependency.
|
||||
|
||||
Data in NumPy arrays is not guaranteed to packed in a dense manner;
|
||||
furthermore, entries can be separated by arbitrary column and row strides.
|
||||
@@ -169,6 +171,31 @@ template parameter, and it ensures that non-conforming arguments are converted
|
||||
into an array satisfying the specified requirements instead of trying the next
|
||||
function overload.
|
||||
|
||||
There are several methods on arrays; the methods listed below under references
|
||||
work, as well as the following functions based on the NumPy API:
|
||||
|
||||
- ``.dtype()`` returns the type of the contained values.
|
||||
|
||||
- ``.strides()`` returns a pointer to the strides of the array (optionally pass
|
||||
an integer axis to get a number).
|
||||
|
||||
- ``.flags()`` returns the flag settings. ``.writable()`` and ``.owndata()``
|
||||
are directly available.
|
||||
|
||||
- ``.offset_at()`` returns the offset (optionally pass indices).
|
||||
|
||||
- ``.squeeze()`` returns a view with length-1 axes removed.
|
||||
|
||||
- ``.view(dtype)`` returns a view of the array with a different dtype.
|
||||
|
||||
- ``.reshape({i, j, ...})`` returns a view of the array with a different shape.
|
||||
``.resize({...})`` is also available.
|
||||
|
||||
- ``.index_at(i, j, ...)`` gets the count from the beginning to a given index.
|
||||
|
||||
|
||||
There are also several methods for getting references (described below).
|
||||
|
||||
Structured types
|
||||
================
|
||||
|
||||
@@ -231,8 +258,8 @@ by the compiler. The result is returned as a NumPy array of type
|
||||
|
||||
.. code-block:: pycon
|
||||
|
||||
>>> x = np.array([[1, 3],[5, 7]])
|
||||
>>> y = np.array([[2, 4],[6, 8]])
|
||||
>>> x = np.array([[1, 3], [5, 7]])
|
||||
>>> y = np.array([[2, 4], [6, 8]])
|
||||
>>> z = 3
|
||||
>>> result = vectorized_func(x, y, z)
|
||||
|
||||
@@ -343,21 +370,19 @@ The returned proxy object supports some of the same methods as ``py::array`` so
|
||||
that it can be used as a drop-in replacement for some existing, index-checked
|
||||
uses of ``py::array``:
|
||||
|
||||
- ``r.ndim()`` returns the number of dimensions
|
||||
- ``.ndim()`` returns the number of dimensions
|
||||
|
||||
- ``r.data(1, 2, ...)`` and ``r.mutable_data(1, 2, ...)``` returns a pointer to
|
||||
- ``.data(1, 2, ...)`` and ``r.mutable_data(1, 2, ...)``` returns a pointer to
|
||||
the ``const T`` or ``T`` data, respectively, at the given indices. The
|
||||
latter is only available to proxies obtained via ``a.mutable_unchecked()``.
|
||||
|
||||
- ``itemsize()`` returns the size of an item in bytes, i.e. ``sizeof(T)``.
|
||||
- ``.itemsize()`` returns the size of an item in bytes, i.e. ``sizeof(T)``.
|
||||
|
||||
- ``ndim()`` returns the number of dimensions.
|
||||
- ``.shape(n)`` returns the size of dimension ``n``
|
||||
|
||||
- ``shape(n)`` returns the size of dimension ``n``
|
||||
- ``.size()`` returns the total number of elements (i.e. the product of the shapes).
|
||||
|
||||
- ``size()`` returns the total number of elements (i.e. the product of the shapes).
|
||||
|
||||
- ``nbytes()`` returns the number of bytes used by the referenced elements
|
||||
- ``.nbytes()`` returns the number of bytes used by the referenced elements
|
||||
(i.e. ``itemsize()`` times ``size()``).
|
||||
|
||||
.. seealso::
|
||||
@@ -368,15 +393,13 @@ uses of ``py::array``:
|
||||
Ellipsis
|
||||
========
|
||||
|
||||
Python 3 provides a convenient ``...`` ellipsis notation that is often used to
|
||||
Python provides a convenient ``...`` ellipsis notation that is often used to
|
||||
slice multidimensional arrays. For instance, the following snippet extracts the
|
||||
middle dimensions of a tensor with the first and last index set to zero.
|
||||
In Python 2, the syntactic sugar ``...`` is not available, but the singleton
|
||||
``Ellipsis`` (of type ``ellipsis``) can still be used directly.
|
||||
|
||||
.. code-block:: python
|
||||
|
||||
a = # a NumPy array
|
||||
a = ... # a NumPy array
|
||||
b = a[0, ..., 0]
|
||||
|
||||
The function ``py::ellipsis()`` function can be used to perform the same
|
||||
@@ -387,8 +410,6 @@ operation on the C++ side:
|
||||
py::array a = /* A NumPy array */;
|
||||
py::array b = a[py::make_tuple(0, py::ellipsis(), 0)];
|
||||
|
||||
.. versionchanged:: 2.6
|
||||
``py::ellipsis()`` is now also avaliable in Python 2.
|
||||
|
||||
Memory view
|
||||
===========
|
||||
@@ -410,7 +431,7 @@ following:
|
||||
{ 2, 4 }, // shape (rows, cols)
|
||||
{ sizeof(uint8_t) * 4, sizeof(uint8_t) } // strides in bytes
|
||||
);
|
||||
})
|
||||
});
|
||||
|
||||
This approach is meant for providing a ``memoryview`` for a C/C++ buffer not
|
||||
managed by Python. The user is responsible for managing the lifetime of the
|
||||
@@ -426,11 +447,7 @@ We can also use ``memoryview::from_memory`` for a simple 1D contiguous buffer:
|
||||
buffer, // buffer pointer
|
||||
sizeof(uint8_t) * 8 // buffer size
|
||||
);
|
||||
})
|
||||
|
||||
.. note::
|
||||
|
||||
``memoryview::from_memory`` is not available in Python 2.
|
||||
});
|
||||
|
||||
.. versionchanged:: 2.6
|
||||
``memoryview::from_memory`` added.
|
||||
|
||||
@@ -20,6 +20,40 @@ Available types include :class:`handle`, :class:`object`, :class:`bool_`,
|
||||
Be sure to review the :ref:`pytypes_gotchas` before using this heavily in
|
||||
your C++ API.
|
||||
|
||||
.. _instantiating_compound_types:
|
||||
|
||||
Instantiating compound Python types from C++
|
||||
============================================
|
||||
|
||||
Dictionaries can be initialized in the :class:`dict` constructor:
|
||||
|
||||
.. code-block:: cpp
|
||||
|
||||
using namespace pybind11::literals; // to bring in the `_a` literal
|
||||
py::dict d("spam"_a=py::none(), "eggs"_a=42);
|
||||
|
||||
A tuple of python objects can be instantiated using :func:`py::make_tuple`:
|
||||
|
||||
.. code-block:: cpp
|
||||
|
||||
py::tuple tup = py::make_tuple(42, py::none(), "spam");
|
||||
|
||||
Each element is converted to a supported Python type.
|
||||
|
||||
A `simple namespace`_ can be instantiated using
|
||||
|
||||
.. code-block:: cpp
|
||||
|
||||
using namespace pybind11::literals; // to bring in the `_a` literal
|
||||
py::object SimpleNamespace = py::module_::import("types").attr("SimpleNamespace");
|
||||
py::object ns = SimpleNamespace("spam"_a=py::none(), "eggs"_a=42);
|
||||
|
||||
Attributes on a namespace can be modified with the :func:`py::delattr`,
|
||||
:func:`py::getattr`, and :func:`py::setattr` functions. Simple namespaces can
|
||||
be useful as lightweight stand-ins for class instances.
|
||||
|
||||
.. _simple namespace: https://docs.python.org/3/library/types.html#types.SimpleNamespace
|
||||
|
||||
.. _casting_back_and_forth:
|
||||
|
||||
Casting back and forth
|
||||
@@ -30,7 +64,7 @@ types to Python, which can be done using :func:`py::cast`:
|
||||
|
||||
.. code-block:: cpp
|
||||
|
||||
MyClass *cls = ..;
|
||||
MyClass *cls = ...;
|
||||
py::object obj = py::cast(cls);
|
||||
|
||||
The reverse direction uses the following syntax:
|
||||
@@ -132,6 +166,7 @@ Keyword arguments are also supported. In Python, there is the usual call syntax:
|
||||
def f(number, say, to):
|
||||
... # function code
|
||||
|
||||
|
||||
f(1234, say="hello", to=some_instance) # keyword call in Python
|
||||
|
||||
In C++, the same call can be made using:
|
||||
|
||||
@@ -28,7 +28,7 @@ Capturing standard output from ostream
|
||||
|
||||
Often, a library will use the streams ``std::cout`` and ``std::cerr`` to print,
|
||||
but this does not play well with Python's standard ``sys.stdout`` and ``sys.stderr``
|
||||
redirection. Replacing a library's printing with `py::print <print>` may not
|
||||
redirection. Replacing a library's printing with ``py::print <print>`` may not
|
||||
be feasible. This can be fixed using a guard around the library function that
|
||||
redirects output to the corresponding Python streams:
|
||||
|
||||
@@ -47,15 +47,26 @@ redirects output to the corresponding Python streams:
|
||||
call_noisy_func();
|
||||
});
|
||||
|
||||
.. warning::
|
||||
|
||||
The implementation in ``pybind11/iostream.h`` is NOT thread safe. Multiple
|
||||
threads writing to a redirected ostream concurrently cause data races
|
||||
and potentially buffer overflows. Therefore it is currently a requirement
|
||||
that all (possibly) concurrent redirected ostream writes are protected by
|
||||
a mutex. #HelpAppreciated: Work on iostream.h thread safety. For more
|
||||
background see the discussions under
|
||||
`PR #2982 <https://github.com/pybind/pybind11/pull/2982>`_ and
|
||||
`PR #2995 <https://github.com/pybind/pybind11/pull/2995>`_.
|
||||
|
||||
This method respects flushes on the output streams and will flush if needed
|
||||
when the scoped guard is destroyed. This allows the output to be redirected in
|
||||
real time, such as to a Jupyter notebook. The two arguments, the C++ stream and
|
||||
the Python output, are optional, and default to standard output if not given. An
|
||||
extra type, `py::scoped_estream_redirect <scoped_estream_redirect>`, is identical
|
||||
extra type, ``py::scoped_estream_redirect <scoped_estream_redirect>``, is identical
|
||||
except for defaulting to ``std::cerr`` and ``sys.stderr``; this can be useful with
|
||||
`py::call_guard`, which allows multiple items, but uses the default constructor:
|
||||
``py::call_guard``, which allows multiple items, but uses the default constructor:
|
||||
|
||||
.. code-block:: py
|
||||
.. code-block:: cpp
|
||||
|
||||
// Alternative: Call single function using call guard
|
||||
m.def("noisy_func", &call_noisy_function,
|
||||
@@ -63,7 +74,7 @@ except for defaulting to ``std::cerr`` and ``sys.stderr``; this can be useful wi
|
||||
py::scoped_estream_redirect>());
|
||||
|
||||
The redirection can also be done in Python with the addition of a context
|
||||
manager, using the `py::add_ostream_redirect() <add_ostream_redirect>` function:
|
||||
manager, using the ``py::add_ostream_redirect() <add_ostream_redirect>`` function:
|
||||
|
||||
.. code-block:: cpp
|
||||
|
||||
@@ -92,7 +103,7 @@ arguments to disable one of the streams if needed.
|
||||
Evaluating Python expressions from strings and files
|
||||
====================================================
|
||||
|
||||
pybind11 provides the `eval`, `exec` and `eval_file` functions to evaluate
|
||||
pybind11 provides the ``eval``, ``exec`` and ``eval_file`` functions to evaluate
|
||||
Python expressions and statements. The following example illustrates how they
|
||||
can be used.
|
||||
|
||||
|
||||
Reference in New Issue
Block a user