Does a pointer get freed when called indirectly in a function from a struct? Question: Say we have the following in Cython: ctypedef struct Structure: int* array int size cdef print_fx(Structure obj): print(obj.array[0]) cdef create_object(int size): cdef Structure result result.size = size result.array = <int*>malloc(size*sizeof(int)) for i in range(size): result.array[i] = 1 return result And …
Cython: Passing pointer created by Python wrapper class to C function Question: I am following the Cython Documentation to define a class that is created from an existing C pointer: # Example C struct ctypedef struct my_c_struct: int a int b cdef class WrapperClass: """A wrapper class for a C/C++ data structure""" cdef my_c_struct *_ptr …
Cython: Aliasing function argument name Question: I have a C library that I am writing a Python extension for using Cython that includes this function (declared in the library’s header file): #include <stdio.h> #include "zlib.h" int deflate_index_build(FILE *in, off_t span, struct deflate_index **built); I am attempting to create a Cython extension for this function using: …
Assigning ndarray in cython to new variable very slow? Or what is going on here? Question: I am fairly new to cython and I am wondering why the following takes very long: cpdef test(a): cdef np.ndarray[dtype=int] b for i in range(10): b=a a=np.array([1,2,3],dtype=int) t = timeit.Timer(functools.partial(test.test, a)) print(t.timeit(1000000)) -> 0.5446977 Seconds If i comment out …
As of 2023, is there any way to line profile Cython at all? Question: Something has substantially changed with the way that line profiling Cython works, such that previous answers no longer work. I am not sure if something subtle has changed, or if it is simply totally broken. For instance, here is a very …
Poetry add dependency that uses cython Question: I have a project which needs to depend on the latest commit of pysam, because I’m working in python 3.11. This means building the package from source, so I do the following: poetry add git+https://github.com/pysam-developers/pysam However, I get an error which I think boils down to poetry not …
Using pypa's build on a python project leads to a generic "none-any.whl" wheel, but the package has OS-specific binaries (cython) Question: I am trying to build a package for distribution which has cython code that I would like to compile into binaries before uploading to PyPI. To do this I am using pypa’s build, python …
Spacy add_alias, TypeError Question: MWE from spacy.kb import KnowledgeBase import spacy #kb.add_entity already called. nlp = spacy.blank("en") kb = KnowledgeBase(vocab=nlp.vocab, entity_vector_length=96) name = "test" qid = 1 # type(qid) => int kb.add_alias(alias=name.lower(), entities=[qid], probabilities=[1]) produces the error at the last line: TypeError: an integer is required A previous SO post suggested that the same error …
Cython numpy array view off by one when wraparound is False Question: I have some Cython code where I fill in the last value in each row of a memory view of a NumPy array with a number. If I compile the code with wraparound = False, the last value in the final row of …
How can I extend a built-in type in cython? Question: I’m trying to extend the basic float in python with cython additional methods. I have a python implementation and I know I could create my own extended type by keeping an internal float value. But I’m trying to keep the same code base for interpreted …
