Python is an interpreted, general-purpose high-level programming language whose design philosophy emphasizes code readability.
Questions tagged [python-extensions]
323 questions
1
vote
1 answer
PyLongObject memory leak
There is a memory leak in my encode method.
static const size_t _bits_per_digit = sizeof(digit) * CHAR_BIT;
/**
* Returns a Python int storing the bitstream of the Elias gamma encoded input list.
*/
static PyObject *
encode(PyObject *self,…
theonlygusti
- 11,032
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1
vote
1 answer
Use PyObject_Realloc correctly
https://github.com/python/cpython/blob/master/Include/objimpl.h#L83 says
PyObject_Realloc(p != NULL, 0) does not return NULL, or free the memory at p.
PyObject_Realloc doesn't free the memory.
I've noticed a memory leak in my program which uses…
theonlygusti
- 11,032
- 11
- 64
- 119
1
vote
1 answer
safely handle huge numbers in python extension
Since Python 3 there's no upper limit on the size of an int. I'd like to deal with huge ints of 150+ decimal digits.
This is far larger than a unsigned long long is guaranteed to be, so I don't think I can rely on PyLong_AsLongLong and manipulate…
theonlygusti
- 11,032
- 11
- 64
- 119
1
vote
1 answer
How to build py3-none-any wheels for a project with an optional C extension?
msgpack includes an optional cython
extension. Some users of the package want py3-none-any wheels of msgpack. I'm trying to figure out how to make
it possible to build wheels both with and without the optional extension.
Andrey Bienkowski
- 699
- 3
- 31
1
vote
1 answer
Extending python with non python aware C library?
I would like to create a module that uses a non python aware C library and ctypes.
According to this documentation about creating a C extension to python, I’m required to provide a module initialization function with the signature PyObject*…
chmike
- 20,922
- 21
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1
vote
1 answer
Exposing a new type to python at run time
I have gone through and defined my new types, stored them in a pytypeobject and called the following functions (after initializing the interpreter):
PyType_Ready(); //this takes my defined typed
PyModule_AddObject(); //this adds the defined type to…
DaneEC117
- 227
- 3
- 10
1
vote
0 answers
Initializing an python object from C++ with boost/python returns None
I have a python module that I imported to C++ like this :
.cpp file:
boost::python::object mod;
void init_mod(boost::python::object o){
mod = o;
}
// some code
BOOST_PYTHON_MODULE(MyModule){
def("init_mod", &init_mod);
// for the other…
qwerty_99
- 640
- 5
- 20
1
vote
1 answer
How to return a pointer to a C++ object to python using boost if the class of that object is declared in another boost module?
Okay, maybe I'm not finding an answer because I'm not sure how to word it, but I have a class called Info and another class called Packet, both are compiled into Python extensions using boost, and I would like to return a pointer to an Info object…
qwerty_99
- 640
- 5
- 20
1
vote
1 answer
Trying to understand how reference count works in Python extensions
In my efforts to understand how reference count works in python extensions, I built the following module:
#include
PyObject *value;
static PyObject* pyref_store(PyObject *self, PyObject* args) {
PyArg_ParseTuple(args, "O", &value);
…
bees
- 11
- 3
1
vote
0 answers
How to correctly implement a python iterator in C++?
As a part of a Python module I'm writing in C++ I need to make a type containing an std::vector iterable in Python.
I added a tp_iter function to the type containing the vector that creates an iterator object which has a tp_iternext. The iterator…
SU3
- 5,064
- 3
- 35
- 66
1
vote
1 answer
How to convert a Python deque to a C++ container?
I have to pass a Python deque to a C++ function but I can't find any documentation on how to convert a deque to a C++ container (for this case, either a deque or a vector would do). Searched everywhere but I couldn't find a solution. There's gotta…
qwerty_99
- 640
- 5
- 20
1
vote
0 answers
How fast is PyObject_CallMethod compared to pure python?
I'm trying to optimize some python code by isolating part of the code into a C++ extension. However, since the code is heavily object-oriented, I'll need to set some attributes as PyObject*. My question is how fast is this compared to pure python…
qwerty_99
- 640
- 5
- 20
1
vote
0 answers
Is using the C code to create Python extensions UB in C++ due to lifetime?
There are many tutorials out there on how to create C extensions of Python which introduce a new type. One example: https://docs.python.org/3.5/extending/newtypes.html
This usually boils down to creating a struct like:
struct Example
{
…
Flamefire
- 5,313
- 3
- 35
- 70
1
vote
2 answers
How to instantiate a custom object from within a C module?
I'm having trouble creating an instance of a class (type) I wrote from within the C module. I've written a minimal, self-contained example that illustrates the point. Just copy-paste the three files spam.c, spamtest.py, and setup.py to a directory…
musbur
- 567
- 4
- 16
1
vote
1 answer
Compiling python3 C extensions
I wrote the following code for my CPython extension :
#include
static PyObject *greeting(PyObject* self)
{
return Py_BuildValue("s" , "Hello python modules!!!");
}
static char *my_docstring = "This is a sample docstring";
static…
Parsa Mousavi
- 1,052
- 1
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- 31