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paulrosspaulross
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Add to C++ and Debug sections.
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‎PythonExtensionPatterns/PythonExtensionPatterns.xcodeproj/project.xcworkspace/xcuserdata/paulross.xcuserdatad/UserInterfaceState.xcuserstate

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‎doc/sphinx/source/cpp_and_numpy.rst

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@@ -188,3 +188,100 @@ Supposing you have laid out your source code in the following fashion::
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This is a hybrid of the above and typical for CPython C++ extensions where ``module.c`` contains the CPython code that allows Python to access the pure C++ code.
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The code in ``class.h`` and ``class.cpp`` is unchanged and the code in ``module.c`` is essentially the same as that of a CPython module as described above where ``import_array()`` is called from within the ``PyInit_<module>`` function.
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How These Macros Work Together
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^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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The two macros ``PY_ARRAY_UNIQUE_SYMBOL`` and ``NO_IMPORT_ARRAY`` work together as follows:
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+-----------------------------------+-------------------------------+-------------------------------+
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| | | |
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+-----------------------------------+-------------------------------+-------------------------------+
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| | ``PY_ARRAY_UNIQUE_SYMBOL`` | ``PY_ARRAY_UNIQUE_SYMBOL`` |
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| | NOT defined | defined as <NAME> |
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+-----------------------------------+-------------------------------+-------------------------------+
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| | C API is declared as: | C API is declared as: |
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| ``NO_IMPORT_ARRAY`` not defined | ``static void **PyArray_API`` | ``void **<NAME>`` |
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| | Which makes it only available | so can be seen by other |
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| | to that translation unit. | translation units. |
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+-----------------------------------+-------------------------------+-------------------------------+
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| | C API is declared as: | C API is declared as: |
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| ``NO_IMPORT_ARRAY`` defined | ``extern void **PyArray_API`` | ``extern void **<NAME>`` |
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| | so is available from another | so is available from another |
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| | translation unit. | translation unit. |
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+-----------------------------------+-------------------------------+-------------------------------+
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Adding a Search Path to a Virtual Environment
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^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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If you are linking to the system Python this may not have numpy installed, here is a way to cope with that. Create a virtual environment from the system python and install numpy:
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.. code-block:: bash
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python -m venv <PATH_TO_VIRTUAL_ENVIRONMENT>
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pip install numpy
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Then in your C++ entry point add this function that manipulates ``sys.path``:
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.. code-block:: cpp
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/** Takes a path and adds it to sys.paths by calling PyRun_SimpleString.
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* This does rather laborious C string concatenation so that it will work in
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* a primitive C environment.
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*
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* Returns 0 on success, non-zero on failure.
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*/
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int add_path_to_sys_module(const char *path) {
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int ret = 0;
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const char *prefix = "import sys\nsys.path.append(\"";
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const char *suffix = "\")\n";
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char *command = (char*)malloc(strlen(prefix)
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+ strlen(path)
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+ strlen(suffix)
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+ 1);
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if (! command) {
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return -1;
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}
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strcpy(command, prefix);
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strcat(command, path);
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strcat(command, suffix);
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ret = PyRun_SimpleString(command);
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#ifdef DEBUG
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printf("Calling PyRun_SimpleString() with:\n");
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printf("%s", command);
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printf("PyRun_SimpleString() returned: %d\n", ret);
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fflush(stdout);
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#endif
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free(command);
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return ret;
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}
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``main()`` now calls this with the path to the virtual environment ``site-packages``:
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.. code-block:: cpp
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int main(int argc, const char * argv[]) {
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wchar_t *program = Py_DecodeLocale(argv[0], NULL);
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if (program == NULL) {
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fprintf(stderr, "Fatal error: cannot decode argv[0]\n");
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exit(1);
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}
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// Initialise the interpreter.
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Py_SetProgramName(program); /* optional but recommended */
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Py_Initialize();
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const char *multiarray_path = "<PATH_TO_VIRTUAL_ENVIRONMENT_SITE_PACKAGES>";
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add_path_to_sys_module(multiarray_path);
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import_array();
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if (PyErr_Occurred()) {
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std::cerr << "Failed to import numpy Python module(s)." << std::endl;
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return -1;
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}
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assert(PyArray_API);
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// Your code here...
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}
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‎doc/sphinx/source/debugging/debug_in_ide.rst

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The full code for this is in *src/debugging/XcodeExample/PythonSubclassList/*.
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--------------------------------------------
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Using a Debug Version of Python C with Xcode
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--------------------------------------------
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To get Xcode to use a debug version of Python first build Python from source assumed here to be ``<SOURCE_DIR>`` with, as a minimum, ``--with-pydebug``. This example is using Python 3.6:
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.. code-block:: console
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cd <SOURCE_DIR>
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mkdir debug-framework
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cd debug-framework/
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../configure --with-pydebug --without-pymalloc --with-valgrind --enable-framework
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make
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Then in Xcode select the project and "Add files to ..." and add:
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* ``<SOURCE_DIR>/debug-framework/Python.framework/Versions/3.6/Python``
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* ``<SOURCE_DIR>/debug-framework/libpython3.6d.a``
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In "Build Settings":
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* add ``/Library/Frameworks/Python.framework/Versions/3.6/include/python3.6m/`` to "Header Search Paths". Alternatively add both ``<SOURCE_DIR>/Include`` *and* ``<SOURCE_DIR>/debug-framework`` to "Header Search Paths", the latter is needed for ``pyconfig.h``.
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* add ``<SOURCE_DIR>/debug-framework`` to "Library Search Paths".
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Now you should be able to step into the CPython code.
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--------------------------------------------
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Debugging Python C Extensions in Eclipse
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--------------------------------------------

‎src/debugging/XcodeExample/PythonSubclassList/PythonSubclassList.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist

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<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
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<plist version="1.0">
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<dict>
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<key>IDEDidComputeMac32BitWarning</key>
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<true/>
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</dict>
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</plist>

‎src/debugging/XcodeExample/PythonSubclassList/PythonSubclassList.xcodeproj/project.xcworkspace/xcuserdata/paulross.xcuserdatad/UserInterfaceState.xcuserstate

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‎src/debugging/XcodeExample/PythonSubclassList/PythonSubclassList.xcodeproj/xcuserdata/paulross.xcuserdatad/xcdebugger/Breakpoints_v2.xcbkptlist

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continueAfterRunningActions = "No"
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symbolName = "ScList_append"
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moduleName = "PythonSubclassList"
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usesParentBreakpointCondition = "Yes"
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urlString = "file:///Users/paulross/Documents/workspace/PythonExtensionPatterns/src/debugging/XcodeExample/PythonSubclassList/PythonSubclassList/SubclassList.c"
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timestampString = "486418359.147248"
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continueAfterRunningActions = "No"
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symbolName = "ScList_append"
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moduleName = "ScList.so"
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usesParentBreakpointCondition = "Yes"
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urlString = "file:///Users/paulross/Documents/workspace/PythonExtensionPatterns/src/debugging/XcodeExample/PythonSubclassList/PythonSubclassList/SubclassList.c"
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timestampString = "486418359.297105"
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startingColumnNumber = "9223372036854775807"
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landmarkName = "call_super_pyname"
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landmarkType = "9">
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<Locations>
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<Location
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shouldBeEnabled = "Yes"
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ignoreCount = "0"
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continueAfterRunningActions = "No"
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symbolName = "call_super_pyname"
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moduleName = "PythonSubclassList"
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usesParentBreakpointCondition = "Yes"
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urlString = "file:///Users/paulross/Documents/workspace/PythonExtensionPatterns/src/debugging/XcodeExample/PythonSubclassList/PythonSubclassList/py_call_super.c"
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</Location>
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<Location
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shouldBeEnabled = "Yes"
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continueAfterRunningActions = "No"
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symbolName = "call_super_pyname"
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moduleName = "ScList.so"
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usesParentBreakpointCondition = "Yes"
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urlString = "file:///Users/paulross/Documents/workspace/PythonExtensionPatterns/src/debugging/XcodeExample/PythonSubclassList/PythonSubclassList/py_call_super.c"
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