Cython: Realtime compile_and_load (.pyx)#

An example showing the cython submodule..

# Authors: The scikit-plots developers
# SPDX-License-Identifier: BSD-3-Clause

cython examples#

import scikitplot as sp
sp.__version_iso_8601__

'2026.06.26'

from scikitplot import cython

print(cython.__doc__)

scikitplot.cython
=================
A lightweight runtime Cython development kit with caching, pinning,
garbage collection, and templating support.

:mod:`scikitplot.cython` enables real-time, in-place (in-situ) generation of
low-level Cython packages and modules for immediate use and testing.

.. seealso::
   * https://github.com/cython/cython
   * https://cython.readthedocs.io/en/latest/index.html
   * https://doc.sagemath.org/html/en/reference/misc/sage/misc/cython.html

from scikitplot.cython import compile_and_load
m = compile_and_load("def f(int n):\n    return n*n")
m.f(10)

cython.list_templates()

['basic_cython/t01_square_int', 'basic_cython/t02_add_float', 'basic_cython/t03_toggle_bool', 'basic_cython/t04_repeat_str', 'basic_cython/t05_int_overflow_demo', 'basic_cython/t06_xor_bytes', 'complex_cython/t01_cpp_vector_sum', 'complex_cython/t01_fast_clip', 'complex_cython/t02_nogil_sum', 'complex_cython/t03_nogil_sum', 'complex_cython/t04_nogil_sum', 'complex_cython/t05_popcount64', 'devel_cython/t01_directives', 'devel_cython/t02_cdef_class_counter', 'devel_cython/t03_cdef_class_counter', 'devel_cython/t04_cdef_class_counter', 'devel_cython/t05_cdef_class_counter', 'devel_numcpp_cpp_api_cython/t01_cpp_language', 'devel_numcpp_cpp_api_cython/t01_cpp_memoryview', 'devel_numcpp_cpp_api_cython/t01_numpy_cpp_memoryview', 'devel_numcpp_cpp_api_cython/t02_cpp_vector_size', 'devel_numcpp_cpp_api_cython/t03_cpp_vector_size', 'devel_numpy_c_api_cython/t01_numpy_ndarray_sum', 'devel_numpy_c_api_cython/t01_numpy_typed_ndarray', 'devel_numpy_c_api_cython/t02_numpy_sum_1d', 'devel_numpy_c_api_cython/t03_numpy_sum_1d', 'devel_numpy_c_api_cython/t04_numpy_sum_1d', 'easy_cython/t01_memoryview_sum', 'easy_cython/t01_sum_memoryview', 'easy_cython/t01_sum_view', 'easy_cython/t04_vector_dot_list', 'easy_cython/t05_vector_scale_memview', 'easy_cython/t06_vector_norm2_memview', 'easy_cython/t07_vector_add_list', 'easy_cython/t08_parse_int_ascii', 'hard_cython/t01_cdef_class_counter', 'hard_cython/t01_cdef_class_vector', 'hard_cython/t01_dot_product', 'hard_cython/t02_malloc_fill', 'hard_cython/t03_malloc_fill', 'hard_cython/t04_struct_point_distance', 'medium_cython/t01_fused_add', 'medium_cython/t01_fused_types', 'medium_cython/t01_running_mean', 'medium_cython/t02_fused_add', 'medium_cython/t03_fused_add', 'medium_cython/t04_minmax_memview', 'medium_cython/t05_argmax_memview', 'mixed/t01_square_int', 'mixed/t02_fib_cpdef', 'mixed/t03_cdef_class_counter', 'mixed/t04_memoryview_sum', 'mixed/t05_numpy_ndarray_sum', 'mixed/t06_directives_boundscheck', 'mixed/t07_libc_math', 'mixed/t08_struct_point', 'mixed/t09_enum_state', 'mixed/t10_safe_div_except', 'mixed/t11_fused_types_dot', 'mixed/t12_inline_clamp', 'mixed/t13_bytes_xor', 'mixed/t14_string_reverse', 'mixed/t15_lcg_rng', 'mixed/t16_insertion_sort', 'mixed/t17_kahan_sum', 'mixed/t18_histogram_int', 'mixed/t19_popcount', 'mixed/t20_matmul_small', 'module_cython/t01_counter', 'module_cython/t01_extension_class', 'module_cython/t01_module_constants', 'module_cython/t02_cdef_class_counter', 'module_cython/t03_cdef_class_counter', 'module_cython/t90_include_pxi_square', 'module_cython/t91_extern_header_add']

cython.get_template_path(cython.list_templates()[0])

PosixPath('/home/circleci/.pyenv/versions/3.12.13/lib/python3.12/site-packages/scikitplot/cython/_templates/basic_cython/t01_square_int.pyx')

print(cython.read_template(cython.list_templates()[0]))

# cython: language_level=3
"""Basic Cython template: typed function.

This demonstrates a minimal compiled function with C integer typing.
"""


def square(int n):
    """Return n*n using C integer arithmetic."""
    return n * n

cython.get_cache_dir()

PosixPath('/home/circleci/.cache/scikitplot/cython')

cython.list_cached()

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artifact_path=PosixPath('/home/circleci/.cache/scikitplot/cython/102bfbd99ec33aaf397db7f537c04e28ea5be67d18d08aba5f4fcc28d9a7d443/scikitplot_cython_102bfbd99ec33aaf.cpython-312-x86_64-linux-gnu.so'), created_utc='2026-06-26T18:49:03Z', fingerprint={'abi': '', 'cython': '3.2.6', 'machine': 'x86_64', 'numpy': '2.4.6', 'platform': 'Linux-6.17.0-1013-aws-x86_64-with-glibc2.35', 'processor': 'x86_64', 'python': '3.12.13', 'python_impl': 'CPython'}), CacheEntry(key='4124d7284c7886e12d7a671bb88f05003039cded41c1addbc5442107bb51454f', build_dir=PosixPath('/home/circleci/.cache/scikitplot/cython/4124d7284c7886e12d7a671bb88f05003039cded41c1addbc5442107bb51454f'), module_name='wf_ext_square', artifact_path=PosixPath('/home/circleci/.cache/scikitplot/cython/4124d7284c7886e12d7a671bb88f05003039cded41c1addbc5442107bb51454f/wf_ext_square.cpython-312-x86_64-linux-gnu.so'), created_utc='2026-06-26T18:49:23Z', fingerprint={'abi': '', 'cython': '3.2.6', 'machine': 'x86_64', 'numpy': '2.4.6', 'platform': 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build_dir=PosixPath('/home/circleci/.cache/scikitplot/cython/8c86efd9d53684b165468c85bf4fd11e1a7de61d6cdde0075a3e0507cfaf424c'), module_name='scikitplot_cython_8c86efd9d53684b1', artifact_path=PosixPath('/home/circleci/.cache/scikitplot/cython/8c86efd9d53684b165468c85bf4fd11e1a7de61d6cdde0075a3e0507cfaf424c/scikitplot_cython_8c86efd9d53684b1.cpython-312-x86_64-linux-gnu.so'), created_utc='2026-06-26T18:49:00Z', fingerprint={'abi': '', 'cython': '3.2.6', 'machine': 'x86_64', 'numpy': '2.4.6', 'platform': 'Linux-6.17.0-1013-aws-x86_64-with-glibc2.35', 'processor': 'x86_64', 'python': '3.12.13', 'python_impl': 'CPython'}), CacheEntry(key='9babdf95708f568326fe5fae285b0a76baf3a9f8b0c287f973c22f0f71cfc87e', build_dir=PosixPath('/home/circleci/.cache/scikitplot/cython/9babdf95708f568326fe5fae285b0a76baf3a9f8b0c287f973c22f0f71cfc87e'), module_name='multifile_demo', 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'x86_64', 'numpy': '2.4.6', 'platform': 'Linux-6.17.0-1013-aws-x86_64-with-glibc2.35', 'processor': 'x86_64', 'python': '3.12.13', 'python_impl': 'CPython'}), CacheEntry(key='ffe085a82700e9551549a99938c76fa742845298370db4b9b703187ff09d8efd', build_dir=PosixPath('/home/circleci/.cache/scikitplot/cython/ffe085a82700e9551549a99938c76fa742845298370db4b9b703187ff09d8efd'), module_name='scikitplot_cython_ffe085a82700e955', artifact_path=PosixPath('/home/circleci/.cache/scikitplot/cython/ffe085a82700e9551549a99938c76fa742845298370db4b9b703187ff09d8efd/scikitplot_cython_ffe085a82700e955.cpython-312-x86_64-linux-gnu.so'), created_utc='2026-06-26T18:49:05Z', fingerprint={'abi': '', 'cython': '3.2.6', 'machine': 'x86_64', 'numpy': '2.4.6', 'platform': 'Linux-6.17.0-1013-aws-x86_64-with-glibc2.35', 'processor': 'x86_64', 'python': '3.12.13', 'python_impl': 'CPython'})]

cython.list_cached()[0].build_dir

PosixPath('/home/circleci/.cache/scikitplot/cython/079973d842a339642538be793f6acc790489c08f6e0d8a84e9d3a33a74002c6a')

cython.list_cached()[0].artifact_path

PosixPath('/home/circleci/.cache/scikitplot/cython/079973d842a339642538be793f6acc790489c08f6e0d8a84e9d3a33a74002c6a/memview_scale_demo.cpython-312-x86_64-linux-gnu.so')

from scikitplot.cython import compile_template

m = compile_template(cython.list_templates()[2])
m = compile_template(cython.list_templates()[1])
m = compile_template(cython.list_templates()[0])
m.square(12)

m = compile_template('module_cython/t01_counter')
m

<module 'scikitplot_cython_4f8b4688b0c26703' from '/home/circleci/.cache/scikitplot/cython/4f8b4688b0c26703cce8bee8317b92ec6ba22c6f97bc2fc786585d5f9ae85211/scikitplot_cython_4f8b4688b0c26703.cpython-312-x86_64-linux-gnu.so'>