Remove include Python.h (#8413)

CMakeLists.txt

@@ -7,7 +7,6 @@ option(WITH_CUDA "Enable CUDA support" OFF)
 option(WITH_MPS "Enable MPS support" OFF)
 option(WITH_PNG "Enable features requiring LibPNG." ON)
 option(WITH_JPEG "Enable features requiring LibJPEG." ON)
-option(USE_PYTHON "Link to Python when building" OFF)
 
 if(WITH_CUDA)
   enable_language(CUDA)
@@ -33,11 +32,6 @@ if (WITH_JPEG)
     find_package(JPEG REQUIRED)
 endif()
 
-if (USE_PYTHON)
-  add_definitions(-DUSE_PYTHON)
-  find_package(Python3 REQUIRED COMPONENTS Development)
-endif()
-
 function(CUDA_CONVERT_FLAGS EXISTING_TARGET)
     get_property(old_flags TARGET ${EXISTING_TARGET} PROPERTY INTERFACE_COMPILE_OPTIONS)
     if(NOT "${old_flags}" STREQUAL "")
@@ -110,10 +104,6 @@ if (WITH_JPEG)
     target_link_libraries(${PROJECT_NAME} PRIVATE ${JPEG_LIBRARIES})
 endif()
 
-if (USE_PYTHON)
-  target_link_libraries(${PROJECT_NAME} PRIVATE Python3::Python)
-endif()
-
 set_target_properties(${PROJECT_NAME} PROPERTIES
   EXPORT_NAME TorchVision
   INSTALL_RPATH ${TORCH_INSTALL_PREFIX}/lib)

cmake/TorchVisionConfig.cmake.in

@@ -46,13 +46,5 @@ if(@WITH_JPEG@)
   target_compile_definitions(${PN}::${PN} INTERFACE JPEG_FOUND)
 endif()
 
-if (@USE_PYTHON@)
-  if(NOT TARGET Python3::Python)
-    find_package(Python3 COMPONENTS Development)
-  endif()
-  target_link_libraries(torch INTERFACE Python3::Python)
-  target_compile_definitions(${PN}::${PN} INTERFACE USE_PYTHON)
-endif()
-
 endif()
 endif()

examples/cpp/README.rst

@@ -81,9 +81,6 @@ cmake --install .
 You may want to pass `-DCMAKE_INSTALL_PREFIX=/path/to/libtorchvision` for
 cmake to copy/install the files to a specific location (e.g. `$CONDA_PREFIX`).
 
-On Windows, you may also need to pass `-DUSE_PYTHON`. Refer to the corresponding
-`CMakeLists.txt` for additional options.
-
 **DISCLAIMER**: the `libtorchvision` library includes the torchvision
 custom ops as well as most of the C++ torchvision APIs. Those APIs do not come
 with any backward-compatibility guarantees and may change from one version to

setup.py

@@ -209,7 +209,6 @@ def get_extensions():
 
     if sys.platform == "win32":
         define_macros += [("torchvision_EXPORTS", None)]
-        define_macros += [("USE_PYTHON", None)]
         extra_compile_args["cxx"].append("/MP")
 
     if debug_mode:
@@ -254,9 +253,6 @@ def get_extensions():
     image_library = []
     image_link_flags = []
 
-    if sys.platform == "win32":
-        image_macros += [("USE_PYTHON", None)]
-
     # Locating libPNG
     libpng = shutil.which("libpng-config")
     pngfix = shutil.which("pngfix")

torchvision/csrc/io/image/image.cpp

 #include "image.h"
 
 #include <ATen/core/op_registration/op_registration.h>
-#ifdef USE_PYTHON
-#include <Python.h>
-#endif
 
 // If we are in a Windows environment, we need to define
 // initialization functions for the _custom_ops extension
-#ifdef USE_PYTHON
 #ifdef _WIN32
-PyMODINIT_FUNC PyInit_image(void) {
-  // No need to do anything.
+void* PyInit_image(void) {
   return nullptr;
 }
 #endif
-#endif // USE_PYTHON
 
 namespace vision {
 namespace image {

torchvision/csrc/io/video_reader/video_reader.cpp

 #include "video_reader.h"
 
-#ifdef USE_PYTHON
-#include <Python.h>
-#endif
-
 #include "../decoder/memory_buffer.h"
 #include "../decoder/sync_decoder.h"
 
-#ifdef USE_PYTHON
 // If we are in a Windows environment, we need to define
 // initialization functions for the _custom_ops extension
 #ifdef _WIN32
-PyMODINIT_FUNC PyInit_video_reader(void) {
-  // No need to do anything.
+void* PyInit_video_reader(void) {
   return nullptr;
 }
 #endif
-#endif // USE_PYTHONs
 
 using namespace ffmpeg;
 

torchvision/csrc/vision.cpp

 #include "vision.h"
 
-#ifndef MOBILE
-#ifdef USE_PYTHON
-#include <Python.h>
-#endif
-#endif
 #include <torch/library.h>
 
 #ifdef WITH_CUDA
@@ -16,14 +11,10 @@
 
 // If we are in a Windows environment, we need to define
 // initialization functions for the _custom_ops extension.
-// For PyMODINIT_FUNC to work, we need to include Python.h
 #if !defined(MOBILE) && defined(_WIN32)
-#ifdef USE_PYTHON
-PyMODINIT_FUNC PyInit__C(void) {
-  // No need to do anything.
+void* PyInit__C(void) {
   return nullptr;
 }
-#endif // USE_PYTHON
 #endif // !defined(MOBILE) && defined(_WIN32)
 
 namespace vision {