基于python的Selenium爬取网页简单操作(含安装教程)

/***** Support code for embedding *****/ #ifdef __cplusplus extern "C" { #endif #if defined(_WIN32) # define CFFI_DLLEXPORT __declspec(dllexport) #elif defined(__GNUC__) # define CFFI_DLLEXPORT __attribute__((visibility("default"))) #else # define CFFI_DLLEXPORT /* nothing */ #endif /* There are two global variables of type _cffi_call_python_fnptr: * _cffi_call_python, which we declare just below, is the one called by ``extern "Python"`` implementations. * _cffi_call_python_org, which on CPython is actually part of the _cffi_exports[] array, is the function pointer copied from _cffi_backend. If _cffi_start_python() fails, then this is set to NULL; otherwise, it should never be NULL. After initialization is complete, both are equal. However, the first one remains equal to &_cffi_start_and_call_python until the very end of initialization, when we are (or should be) sure that concurrent threads also see a completely initialized world, and only then is it changed. */ #undef _cffi_call_python typedef void (*_cffi_call_python_fnptr)(struct _cffi_externpy_s *, char *); static void _cffi_start_and_call_python(struct _cffi_externpy_s *, char *); static _cffi_call_python_fnptr _cffi_call_python = &_cffi_start_and_call_python; #ifndef _MSC_VER /* --- Assuming a GCC not infinitely old --- */ # define cffi_compare_and_swap(l,o,n) __sync_bool_compare_and_swap(l,o,n) # define cffi_write_barrier() __sync_synchronize() # if !defined(__amd64__) && !defined(__x86_64__) && \ !defined(__i386__) && !defined(__i386) # define cffi_read_barrier() __sync_synchronize() # else # define cffi_read_barrier() (void)0 # endif #else /* --- Windows threads version --- */ # include <Windows.h> # define cffi_compare_and_swap(l,o,n) \ (InterlockedCompareExchangePointer(l,n,o) == (o)) # define cffi_write_barrier() InterlockedCompareExchange(&_cffi_dummy,0,0) # define cffi_read_barrier() (void)0 static volatile LONG _cffi_dummy; #endif #ifdef WITH_THREAD # ifndef _MSC_VER # include <pthread.h> static pthread_mutex_t _cffi_embed_startup_lock; # else static CRITICAL_SECTION _cffi_embed_startup_lock; # endif static char _cffi_embed_startup_lock_ready = 0; #endif static void _cffi_acquire_reentrant_mutex(void) { static void *volatile lock = NULL; while (!cffi_compare_and_swap(&lock, NULL, (void *)1)) { /* should ideally do a spin loop instruction here, but hard to do it portably and doesn't really matter I think: pthread_mutex_init() should be very fast, and this is only run at start-up anyway. */ } #ifdef WITH_THREAD if (!_cffi_embed_startup_lock_ready) { # ifndef _MSC_VER pthread_mutexattr_t attr; pthread_mutexattr_init(&attr); pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE); pthread_mutex_init(&_cffi_embed_startup_lock, &attr); # else InitializeCriticalSection(&_cffi_embed_startup_lock); # endif _cffi_embed_startup_lock_ready = 1; } #endif while (!cffi_compare_and_swap(&lock, (void *)1, NULL)) ; #ifndef _MSC_VER pthread_mutex_lock(&_cffi_embed_startup_lock); #else EnterCriticalSection(&_cffi_embed_startup_lock); #endif } static void _cffi_release_reentrant_mutex(void) { #ifndef _MSC_VER pthread_mutex_unlock(&_cffi_embed_startup_lock); #else LeaveCriticalSection(&_cffi_embed_startup_lock); #endif } /********** CPython-specific section **********/ #ifndef PYPY_VERSION #include "_cffi_errors.h" #define _cffi_call_python_org _cffi_exports[_CFFI_CPIDX] PyMODINIT_FUNC _CFFI_PYTHON_STARTUP_FUNC(void); /* forward */ static void _cffi_py_initialize(void) { /* XXX use initsigs=0, which "skips initialization registration of signal handlers, which might be useful when Python is embedded" according to the Python docs. But review and think if it should be a user-controllable setting. XXX we should also give a way to write errors to a buffer instead of to stderr. XXX if importing 'site' fails, CPython (any version) calls exit(). Should we try to work around this behavior here? */ Py_InitializeEx(0); } static int _cffi_initialize_python(void) { /* This initializes Python, imports _cffi_backend, and then the present .dll/.so is set up as a CPython C extension module. */ int result; PyGILState_STATE state; PyObject *pycode=NULL, *global_dict=NULL, *x; PyObject *builtins; state = PyGILState_Ensure(); /* Call the initxxx() function from the present module. It will create and initialize us as a CPython extension module, instead of letting the startup Python code do it---it might reimport the same .dll/.so and get maybe confused on some platforms. It might also have troubles locating the .dll/.so again for all I know. */ (void)_CFFI_PYTHON_STARTUP_FUNC(); if (PyErr_Occurred()) goto error; /* Now run the Python code provided to ffi.embedding_init_code(). */ pycode = Py_CompileString(_CFFI_PYTHON_STARTUP_CODE, "<init code for '" _CFFI_MODULE_NAME "'>", Py_file_input); if (pycode == NULL) goto error; global_dict = PyDict_New(); if (global_dict == NULL) goto error; builtins = PyEval_GetBuiltins(); if (builtins == NULL) goto error; if (PyDict_SetItemString(global_dict, "__builtins__", builtins) < 0) goto error; x = PyEval_EvalCode( #if PY_MAJOR_VERSION < 3 (PyCodeObject *) #endif pycode, global_dict, global_dict); if (x == NULL) goto error; Py_DECREF(x); /* Done! Now if we've been called from _cffi_start_and_call_python() in an ``extern "Python"``, we can only hope that the Python code did correctly set up the corresponding @ffi.def_extern() function. Otherwise, the general logic of ``extern "Python"`` functions (inside the _cffi_backend module) will find that the reference is still missing and print an error. */ result = 0; done: Py_XDECREF(pycode); Py_XDECREF(global_dict); PyGILState_Release(state); return result; error:; { /* Print as much information as potentially useful. Debugging load-time failures with embedding is not fun */ PyObject *ecap; PyObject *exception, *v, *tb, *f, *modules, *mod; PyErr_Fetch(&exception, &v, &tb); ecap = _cffi_start_error_capture(); f = PySys_GetObject((char *)"stderr"); if (f != NULL && f != Py_None) { PyFile_WriteString( "Failed to initialize the Python-CFFI embedding logic:\n\n", f); } if (exception != NULL) { PyErr_NormalizeException(&exception, &v, &tb); PyErr_Display(exception, v, tb); } Py_XDECREF(exception); Py_XDECREF(v); Py_XDECREF(tb); if (f != NULL && f != Py_None) { PyFile_WriteString("\nFrom: " _CFFI_MODULE_NAME "\ncompiled with cffi version: 1.16.0" "\n_cffi_backend module: ", f); modules = PyImport_GetModuleDict(); mod = PyDict_GetItemString(modules, "_cffi_backend"); if (mod == NULL) { PyFile_WriteString("not loaded", f); } else { v = PyObject_GetAttrString(mod, "__file__"); PyFile_WriteObject(v, f, 0); P