异常处理 ¶

本章节中描述的函数将让您处理和引发 Python 异常。理解一些 Python 异常处理的基础知识很重要。它的工作原理有点像 POSIX errno 变量：最后发生的错误有全局指示器 (每线程)。大多数 C API 函数不会清零它当成功时，但会设置它以指示出错原因当失败时。大多数 C API 函数还返回错误指示器，通常是 NULL 若假设它们要返回指针，或者 -1 若它们返回整数 (例外： PyArg_* 函数返回 1 对于成功和 0 对于故障)。

Concretely, the error indicator consists of three object pointers: the exception’s type, the exception’s value, and the traceback object. Any of those pointers can be NULL if non-set (although some combinations are forbidden, for example you can’t have a non- NULL traceback if the exception type is NULL ).

当函数因调用的某个函数失败而必须失败时，一般不设置错误指示器；它调用的函数已有设置。它负责处理错误和清零异常或在清理它保持的任何资源后返回 (譬如：对象引用或内存分配)；它应该 not 继续通常，若不准备处理错误。若由于错误而返回，重要的是向调用者指示有设置错误。若错误未被处理或被小心谨慎地传播，对 Python/C API 的额外调用可能没有如打算般的行为，且可能以神秘方式失败。

注意

错误指示器是 not 结果对于 sys.exc_info() 。前者相当于尚未被捕获的异常 (因此仍在传播)，而后者返回被捕获后的异常 (因此已停止传播)。

打印和清零 ¶

void PyErr_Clear ( ) ¶

属于 稳定 ABI (应用程序二进制接口) .

清零错误指示器。若未设置错误指示器，则没有效果。

void PyErr_PrintEx ( int set_sys_last_vars ) ¶

属于 稳定 ABI (应用程序二进制接口) .

将标准回溯打印到 sys.stderr and clear the error indicator. 除非 the error is a SystemExit , in that case no traceback is printed and the Python process will exit with the error code specified by the SystemExit 实例。

Call this function only when the error indicator is set. Otherwise it will cause a fatal error!

若 set_sys_last_vars 非 0，变量 sys.last_type , sys.last_value and sys.last_traceback 将被分别设为打印异常的类型、值及回溯。

void PyErr_Print ( ) ¶

属于 稳定 ABI (应用程序二进制接口) .

别名化的 PyErr_PrintEx(1) .

void PyErr_WriteUnraisable ( PyObject * obj ) ¶

属于 稳定 ABI (应用程序二进制接口) .

调用 sys.unraisablehook() using the current exception and obj 自变量。

此实用函数将警告消息打印到 sys.stderr 当异常有设置但解释器实际引发异常不可能时。使用它，例如，当异常发生在 __del__() 方法。

调用函数采用单自变量 obj 标识发生不可引发异常的上下文。若可能，repr obj 将被打印在警告消息中。

An exception must be set when calling this function.

引发异常 ¶

These functions help you set the current thread’s error indicator. For convenience, some of these functions will always return a NULL pointer for use in a return 语句。

void PyErr_SetString ( PyObject * type , const char * message ) ¶

属于 稳定 ABI (应用程序二进制接口) .

这是设置错误指示器的最常见方式。首个自变量指定异常类型；它通常是标准异常之一，如 PyExc_RuntimeError 。不需要递增其引用计数。第 2 自变量是错误信息；解码自 'utf-8' .

void PyErr_SetObject ( PyObject * type , PyObject * value ) ¶

属于 稳定 ABI (应用程序二进制接口) .

此函数类似于 PyErr_SetString() 但允许您为异常值指定任意 Python 对象。

PyObject * PyErr_Format ( PyObject * exception , const char * format , ... ) ¶

返回值：始终 NULL。 属于 稳定 ABI (应用程序二进制接口) .

此函数设置错误指示器并返回 NULL . exception 应该是 Python 异常类。 format 和后续参数帮助格式化错误消息；它们拥有相同的意义和值如在 PyUnicode_FromFormat() . format 是 ASCII 编码字符串。

PyObject * PyErr_FormatV ( PyObject * exception , const char * format , va_list vargs ) ¶

返回值：始终 NULL。 属于 稳定 ABI (应用程序二进制接口) since version 3.5.

如同 PyErr_Format() ，但接受 va_list 自变量而不是可变数自变量。

3.5 版新增。

void PyErr_SetNone ( PyObject * type ) ¶

属于 稳定 ABI (应用程序二进制接口) .

这是简写的 PyErr_SetObject(type, Py_None) .

int PyErr_BadArgument ( ) ¶

属于 稳定 ABI (应用程序二进制接口) .

这是简写的 PyErr_SetString(PyExc_TypeError, message) ，其中 message indicates that a built-in operation was invoked with an illegal argument. It is mostly for internal use.

PyObject * PyErr_NoMemory ( ) ¶

返回值：始终 NULL。 属于 稳定 ABI (应用程序二进制接口) .

这是简写的 PyErr_SetNone(PyExc_MemoryError) ；它返回 NULL 因此对象分配函数可以写 return PyErr_NoMemory(); 当耗尽内存时。

PyObject * PyErr_SetFromErrno ( PyObject * type ) ¶

返回值：始终 NULL。 属于 稳定 ABI (应用程序二进制接口) .

这是方便函数以当 C 库函数返回错误时引发异常和设置 C 变量 errno . It constructs a tuple object whose first item is the integer errno value and whose second item is the corresponding error message (gotten from strerror() ), and then calls PyErr_SetObject(type, object) . On Unix, when the errno value is EINTR , indicating an interrupted system call, this calls PyErr_CheckSignals() , and if that set the error indicator, leaves it set to that. The function always returns NULL , so a wrapper function around a system call can write return PyErr_SetFromErrno(type); when the system call returns an error.

PyObject * PyErr_SetFromErrnoWithFilenameObject ( PyObject * type , PyObject * filenameObject ) ¶

返回值：始终 NULL。 属于 稳定 ABI (应用程序二进制接口) .

类似于 PyErr_SetFromErrno() , with the additional behavior that if filenameObject 不是 NULL , it is passed to the constructor of type as a third parameter. In the case of OSError exception, this is used to define the filename attribute of the exception instance.

PyObject * PyErr_SetFromErrnoWithFilenameObjects ( PyObject * type , PyObject * filenameObject , PyObject * filenameObject2 ) ¶

返回值：始终 NULL。 属于 稳定 ABI (应用程序二进制接口) since version 3.7.

类似于 PyErr_SetFromErrnoWithFilenameObject() , but takes a second filename object, for raising errors when a function that takes two filenames fails.

3.4 版新增。

PyObject * PyErr_SetFromErrnoWithFilename ( PyObject * type , const char * filename ) ¶

返回值：始终 NULL。 属于 稳定 ABI (应用程序二进制接口) .

类似于 PyErr_SetFromErrnoWithFilenameObject() , but the filename is given as a C string. filename is decoded from the 文件系统编码和错误处理程序 .

PyObject * PyErr_SetFromWindowsErr ( int ierr ) ¶

返回值：始终 NULL。 属于 稳定 ABI (应用程序二进制接口) on Windows since version 3.7.

这是方便函数以引发 WindowsError . If called with ierr of 0 , the error code returned by a call to GetLastError() is used instead. It calls the Win32 function FormatMessage() to retrieve the Windows description of error code given by ierr or GetLastError() , then it constructs a tuple object whose first item is the ierr value and whose second item is the corresponding error message (gotten from FormatMessage() ), and then calls PyErr_SetObject(PyExc_WindowsError, object) . This function always returns NULL .

可用性 ：Windows。

PyObject * PyErr_SetExcFromWindowsErr ( PyObject * type , int ierr ) ¶

返回值：始终 NULL。 属于 稳定 ABI (应用程序二进制接口) on Windows since version 3.7.

类似于 PyErr_SetFromWindowsErr() , with an additional parameter specifying the exception type to be raised.

可用性 ：Windows。

PyObject * PyErr_SetFromWindowsErrWithFilename ( int ierr , const char * filename ) ¶

返回值：始终 NULL。 属于 稳定 ABI (应用程序二进制接口) on Windows since version 3.7.

类似于 PyErr_SetFromWindowsErrWithFilenameObject() , but the filename is given as a C string. filename is decoded from the filesystem encoding ( os.fsdecode() ).

可用性 ：Windows。

PyObject * PyErr_SetExcFromWindowsErrWithFilenameObject ( PyObject * type , int ierr , PyObject * filename ) ¶

返回值：始终 NULL。 属于 稳定 ABI (应用程序二进制接口) on Windows since version 3.7.

类似于 PyErr_SetFromWindowsErrWithFilenameObject() , with an additional parameter specifying the exception type to be raised.

可用性 ：Windows。

PyObject * PyErr_SetExcFromWindowsErrWithFilenameObjects ( PyObject * type , int ierr , PyObject * filename , PyObject * filename2 ) ¶

返回值：始终 NULL。 属于 稳定 ABI (应用程序二进制接口) on Windows since version 3.7.

类似于 PyErr_SetExcFromWindowsErrWithFilenameObject() , but accepts a second filename object.

可用性 ：Windows。

3.4 版新增。

PyObject * PyErr_SetExcFromWindowsErrWithFilename ( PyObject * type , int ierr , const char * filename ) ¶

返回值：始终 NULL。 属于 稳定 ABI (应用程序二进制接口) on Windows since version 3.7.

类似于 PyErr_SetFromWindowsErrWithFilename() , with an additional parameter specifying the exception type to be raised.

可用性 ：Windows。

PyObject * PyErr_SetImportError ( PyObject * msg , PyObject * name , PyObject * path ) ¶

返回值：始终 NULL。 属于 稳定 ABI (应用程序二进制接口) since version 3.7.

这是方便函数以引发 ImportError . msg will be set as the exception’s message string. name and path , both of which can be NULL , will be set as the ImportError ’s respective name and path 属性。

3.3 版新增。

PyObject * PyErr_SetImportErrorSubclass ( PyObject * exception , PyObject * msg , PyObject * name , PyObject * path ) ¶

返回值：始终 NULL。 属于 稳定 ABI (应用程序二进制接口) since version 3.6.

Much like PyErr_SetImportError() but this function allows for specifying a subclass of ImportError to raise.

3.6 版新增。

void PyErr_SyntaxLocationObject ( PyObject * filename , int lineno , int col_offset ) ¶

Set file, line, and offset information for the current exception. If the current exception is not a SyntaxError , then it sets additional attributes, which make the exception printing subsystem think the exception is a SyntaxError .

3.4 版新增。

void PyErr_SyntaxLocationEx ( const char * filename , int lineno , int col_offset ) ¶

属于 稳定 ABI (应用程序二进制接口) since version 3.7.

像 PyErr_SyntaxLocationObject() ，但 filename is a byte string decoded from the 文件系统编码和错误处理程序 .

3.2 版新增。

void PyErr_SyntaxLocation ( const char * filename , int lineno ) ¶

属于 稳定 ABI (应用程序二进制接口) .

像 PyErr_SyntaxLocationEx() ，但 col_offset parameter is omitted.

void PyErr_BadInternalCall ( ) ¶

属于 稳定 ABI (应用程序二进制接口) .

这是简写的 PyErr_SetString(PyExc_SystemError, message) ，其中 message indicates that an internal operation (e.g. a Python/C API function) was invoked with an illegal argument. It is mostly for internal use.

发出警告 ¶

Use these functions to issue warnings from C code. They mirror similar functions exported by the Python warnings module. They normally print a warning message to sys.stderr ; however, it is also possible that the user has specified that warnings are to be turned into errors, and in that case they will raise an exception. It is also possible that the functions raise an exception because of a problem with the warning machinery. The return value is 0 if no exception is raised, or -1 if an exception is raised. (It is not possible to determine whether a warning message is actually printed, nor what the reason is for the exception; this is intentional.) If an exception is raised, the caller should do its normal exception handling (for example, Py_DECREF() owned references and return an error value).

int PyErr_WarnEx ( PyObject * category , const char * message , Py_ssize_t stack_level ) ¶

属于 稳定 ABI (应用程序二进制接口) .

Issue a warning message. The category argument is a warning category (see below) or NULL ； message argument is a UTF-8 encoded string. stack_level is a positive number giving a number of stack frames; the warning will be issued from the currently executing line of code in that stack frame. A stack_level of 1 is the function calling PyErr_WarnEx() , 2 is the function above that, and so forth.

Warning categories must be subclasses of PyExc_Warning ; PyExc_Warning 是子类化的 PyExc_Exception ; the default warning category is PyExc_RuntimeWarning . The standard Python warning categories are available as global variables whose names are enumerated at 标准警告类别 .

For information about warning control, see the documentation for the warnings module and the -W option in the command line documentation. There is no C API for warning control.

int PyErr_WarnExplicitObject ( PyObject * category , PyObject * message , PyObject * filename , int lineno , PyObject * module , PyObject * registry ) ¶

Issue a warning message with explicit control over all warning attributes. This is a straightforward wrapper around the Python function warnings.warn_explicit() ; see there for more information. The module and registry arguments may be set to NULL to get the default effect described there.

3.4 版新增。

int PyErr_WarnExplicit ( PyObject * category , const char * message , const char * filename , int lineno , const char * module , PyObject * registry ) ¶

属于 稳定 ABI (应用程序二进制接口) .

类似于 PyErr_WarnExplicitObject() 除了 message and module are UTF-8 encoded strings, and filename is decoded from the 文件系统编码和错误处理程序 .

int PyErr_WarnFormat ( PyObject * category , Py_ssize_t stack_level , const char * format , ... ) ¶

属于 稳定 ABI (应用程序二进制接口) .

函数类似于 PyErr_WarnEx() ，但使用 PyUnicode_FromFormat() to format the warning message. format 是 ASCII 编码字符串。

3.2 版新增。

int PyErr_ResourceWarning ( PyObject * source , Py_ssize_t stack_level , const char * format , ... ) ¶

属于 稳定 ABI (应用程序二进制接口) since version 3.6.

函数类似于 PyErr_WarnFormat() ，但 category is ResourceWarning and it passes source to warnings.WarningMessage() .

3.6 版新增。

查询错误指针 ¶

PyObject * PyErr_Occurred ( ) ¶

返回值：借位引用。 属于 稳定 ABI (应用程序二进制接口) .

测试是否有设置错误指示器。若有设置，返回异常 type (首自变量到最后一次调用的一 PyErr_Set* 函数或到 PyErr_Restore() )。若未设置，返回 NULL 。不拥有对返回值的引用，因此不需要 Py_DECREF() 它。

调用者必须保持 GIL (全局解释器锁)。

注意

不要将返回值与特定异常进行比较；使用 PyErr_ExceptionMatches() 代替，如下所示。(比较可能很易失败，因为异常可能是实例而不是类，在类异常的情况下，或它可能是期望异常的子类。)

int PyErr_ExceptionMatches ( PyObject * exc ) ¶

属于 稳定 ABI (应用程序二进制接口) .

相当于 PyErr_GivenExceptionMatches(PyErr_Occurred(), exc) 。这才应该被调用当有实际设置异常时；会发生内存访问违反若没有引发异常。

int PyErr_GivenExceptionMatches ( PyObject * given , PyObject * exc ) ¶

属于 稳定 ABI (应用程序二进制接口) .

返回 True 若 given 异常匹配异常类型在 exc 。若 exc 是类对象，这还返回 True 当 given 是子类的实例。若 exc 是元组，元组 (及子元组递归) 中的所有异常类型都会匹配搜索。

void PyErr_Fetch ( PyObject * * ptype , PyObject * * pvalue , PyObject * * ptraceback ) ¶

属于 稳定 ABI (应用程序二进制接口) .

Retrieve the error indicator into three variables whose addresses are passed. If the error indicator is not set, set all three variables to NULL . If it is set, it will be cleared and you own a reference to each object retrieved. The value and traceback object may be NULL even when the type object is not.

注意

This function is normally only used by code that needs to catch exceptions or by code that needs to save and restore the error indicator temporarily, e.g.:

{
   PyObject *type, *value, *traceback;
   PyErr_Fetch(&type, &value, &traceback);
   /* ... code that might produce other errors ... */
   PyErr_Restore(type, value, traceback);
}
						

void PyErr_Restore ( PyObject * type , PyObject * value , PyObject * traceback ) ¶

属于 稳定 ABI (应用程序二进制接口) .

Set the error indicator from the three objects. If the error indicator is already set, it is cleared first. If the objects are NULL , the error indicator is cleared. Do not pass a NULL type and non- NULL value or traceback. The exception type should be a class. Do not pass an invalid exception type or value. (Violating these rules will cause subtle problems later.) This call takes away a reference to each object: you must own a reference to each object before the call and after the call you no longer own these references. (If you don’t understand this, don’t use this function. I warned you.)

注意

This function is normally only used by code that needs to save and restore the error indicator temporarily. Use PyErr_Fetch() to save the current error indicator.

void PyErr_NormalizeException ( PyObject * * exc , PyObject * * val , PyObject * * tb ) ¶

属于 稳定 ABI (应用程序二进制接口) .

在某些情况下，值的返回通过 PyErr_Fetch() below can be “unnormalized”, meaning that *exc 是类对象但 *val is not an instance of the same class. This function can be used to instantiate the class in that case. If the values are already normalized, nothing happens. The delayed normalization is implemented to improve performance.

注意

This function does not implicitly set the __traceback__ attribute on the exception value. If setting the traceback appropriately is desired, the following additional snippet is needed:

if (tb != NULL) {
  PyException_SetTraceback(val, tb);
}
						

PyObject * PyErr_GetHandledException ( void ) ¶

属于 稳定 ABI (应用程序二进制接口) since version 3.11.

Retrieve the active exception instance, as would be returned by sys.exception() . This refers to an exception that was already caught , not to an exception that was freshly raised. Returns a new reference to the exception or NULL . Does not modify the interpreter’s exception state.

注意

This function is not normally used by code that wants to handle exceptions. Rather, it can be used when code needs to save and restore the exception state temporarily. Use PyErr_SetHandledException() to restore or clear the exception state.

3.11 版新增。

void PyErr_SetHandledException ( PyObject * exc ) ¶

属于 稳定 ABI (应用程序二进制接口) since version 3.11.

Set the active exception, as known from sys.exception() . This refers to an exception that was already caught , not to an exception that was freshly raised. To clear the exception state, pass NULL .

注意

This function is not normally used by code that wants to handle exceptions. Rather, it can be used when code needs to save and restore the exception state temporarily. Use PyErr_GetHandledException() to get the exception state.

3.11 版新增。

void PyErr_GetExcInfo ( PyObject * * ptype , PyObject * * pvalue , PyObject * * ptraceback ) ¶

属于 稳定 ABI (应用程序二进制接口) since version 3.7.

Retrieve the old-style representation of the exception info, as known from sys.exc_info() . This refers to an exception that was already caught , not to an exception that was freshly raised. Returns new references for the three objects, any of which may be NULL . Does not modify the exception info state. This function is kept for backwards compatibility. Prefer using PyErr_GetHandledException() .

注意

This function is not normally used by code that wants to handle exceptions. Rather, it can be used when code needs to save and restore the exception state temporarily. Use PyErr_SetExcInfo() to restore or clear the exception state.

3.3 版新增。

void PyErr_SetExcInfo ( PyObject * type , PyObject * value , PyObject * traceback ) ¶

属于 稳定 ABI (应用程序二进制接口) since version 3.7.

设置异常信息，作为已知来自 sys.exc_info() . This refers to an exception that was already caught , not to an exception that was freshly raised. This function steals the references of the arguments. To clear the exception state, pass NULL for all three arguments. This function is kept for backwards compatibility. Prefer using PyErr_SetHandledException() .

注意

This function is not normally used by code that wants to handle exceptions. Rather, it can be used when code needs to save and restore the exception state temporarily. Use PyErr_GetExcInfo() to read the exception state.

3.3 版新增。

3.11 版改变： type and traceback arguments are no longer used and can be NULL. The interpreter now derives them from the exception instance (the value argument). The function still steals references of all three arguments.

信号处理 ¶

int PyErr_CheckSignals ( ) ¶

属于 稳定 ABI (应用程序二进制接口) .

This function interacts with Python’s signal handling.

If the function is called from the main thread and under the main Python interpreter, it checks whether a signal has been sent to the processes and if so, invokes the corresponding signal handler. If the signal module is supported, this can invoke a signal handler written in Python.

The function attempts to handle all pending signals, and then returns 0 . However, if a Python signal handler raises an exception, the error indicator is set and the function returns -1 immediately (such that other pending signals may not have been handled yet: they will be on the next PyErr_CheckSignals() invocation).

If the function is called from a non-main thread, or under a non-main Python interpreter, it does nothing and returns 0 .

This function can be called by long-running C code that wants to be interruptible by user requests (such as by pressing Ctrl-C).

注意

The default Python signal handler for SIGINT raises the KeyboardInterrupt 异常。

void PyErr_SetInterrupt ( ) ¶

属于 稳定 ABI (应用程序二进制接口) .

模拟效果为 SIGINT signal arriving. This is equivalent to PyErr_SetInterruptEx(SIGINT) .

注意

This function is async-signal-safe. It can be called without the GIL and from a C signal handler.

int PyErr_SetInterruptEx ( int signum ) ¶

属于 稳定 ABI (应用程序二进制接口) since version 3.10.

Simulate the effect of a signal arriving. The next time PyErr_CheckSignals() is called, the Python signal handler for the given signal number will be called.

This function can be called by C code that sets up its own signal handling and wants Python signal handlers to be invoked as expected when an interruption is requested (for example when the user presses Ctrl-C to interrupt an operation).

若给定信号未被 Python 所处理 (被设为 signal.SIG_DFL or signal.SIG_IGN ), it will be ignored.

若 signum is outside of the allowed range of signal numbers, -1 is returned. Otherwise, 0 is returned. The error indicator is never changed by this function.

注意

This function is async-signal-safe. It can be called without the GIL and from a C signal handler.

3.10 版新增。

int PySignal_SetWakeupFd ( int fd ) ¶

This utility function specifies a file descriptor to which the signal number is written as a single byte whenever a signal is received. fd must be non-blocking. It returns the previous such file descriptor.

值 -1 disables the feature; this is the initial state. This is equivalent to signal.set_wakeup_fd() in Python, but without any error checking. fd should be a valid file descriptor. The function should only be called from the main thread.

3.5 版改变： 在 Windows，函数现在还支持套接字句柄。

异常类 ¶

PyObject * PyErr_NewException ( const char * name , PyObject * base , PyObject * dict ) ¶

返回值：新引用。 属于 稳定 ABI (应用程序二进制接口) .

此实用函数创建并返回新的异常类。 name 自变量必须是新异常的名称，C 字符串形式 module.classname 。 base and dict 自变量通常为 NULL 。这创建的类对象派生自 Exception (在 C 中可访问按 PyExc_Exception ).

__module__ attribute of the new class is set to the first part (up to the last dot) of the name argument, and the class name is set to the last part (after the last dot). The base argument can be used to specify alternate base classes; it can either be only one class or a tuple of classes. The dict argument can be used to specify a dictionary of class variables and methods.

PyObject * PyErr_NewExceptionWithDoc ( const char * name , const char * doc , PyObject * base , PyObject * dict ) ¶

返回值：新引用。 属于 稳定 ABI (应用程序二进制接口) .

如同 PyErr_NewException() , except that the new exception class can easily be given a docstring: If doc 为非 NULL , it will be used as the docstring for the exception class.

3.2 版新增。

异常对象 ¶

PyObject * PyException_GetTraceback ( PyObject * ex ) ¶

返回值：新引用。 属于 稳定 ABI (应用程序二进制接口) .

Return the traceback associated with the exception as a new reference, as accessible from Python through __traceback__ . If there is no traceback associated, this returns NULL .

int PyException_SetTraceback ( PyObject * ex , PyObject * tb ) ¶

属于 稳定 ABI (应用程序二进制接口) .

将回溯关联异常设为 tb 。使用 Py_None 以清零它。

PyObject * PyException_GetContext ( PyObject * ex ) ¶

返回值：新引用。 属于 稳定 ABI (应用程序二进制接口) .

Return the context (another exception instance during whose handling ex was raised) associated with the exception as a new reference, as accessible from Python through __context__ . If there is no context associated, this returns NULL .

void PyException_SetContext ( PyObject * ex , PyObject * ctx ) ¶

属于 稳定 ABI (应用程序二进制接口) .

Set the context associated with the exception to ctx 。使用 NULL to clear it. There is no type check to make sure that ctx is an exception instance. This steals a reference to ctx .

PyObject * PyException_GetCause ( PyObject * ex ) ¶

返回值：新引用。 属于 稳定 ABI (应用程序二进制接口) .

返回原因 (异常实例，或 None , set by raise ... from ... ) associated with the exception as a new reference, as accessible from Python through __cause__ .

void PyException_SetCause ( PyObject * ex , PyObject * cause ) ¶

属于 稳定 ABI (应用程序二进制接口) .

Set the cause associated with the exception to cause 。使用 NULL to clear it. There is no type check to make sure that cause is either an exception instance or None . This steals a reference to cause .

__suppress_context__ 被隐式设为 True 通过此函数。

Unicode 异常对象 ¶

The following functions are used to create and modify Unicode exceptions from C.

PyObject * PyUnicodeDecodeError_Create ( const char * encoding , const char * object , Py_ssize_t length , Py_ssize_t start , Py_ssize_t end , const char * reason ) ¶

返回值：新引用。 属于 稳定 ABI (应用程序二进制接口) .

创建 UnicodeDecodeError object with the attributes encoding , object , length , start , end and reason . encoding and reason are UTF-8 encoded strings.

PyObject * PyUnicodeDecodeError_GetEncoding ( PyObject * exc ) ¶

PyObject * PyUnicodeEncodeError_GetEncoding ( PyObject * exc ) ¶

返回值：新引用。 属于 稳定 ABI (应用程序二进制接口) .

返回 encoding 属性为给定异常对象。

PyObject * PyUnicodeDecodeError_GetObject ( PyObject * exc ) ¶

PyObject * PyUnicodeEncodeError_GetObject ( PyObject * exc ) ¶

PyObject * PyUnicodeTranslateError_GetObject ( PyObject * exc ) ¶

返回值：新引用。 属于 稳定 ABI (应用程序二进制接口) .

返回 object 属性为给定异常对象。

int PyUnicodeDecodeError_GetStart ( PyObject * exc , Py_ssize_t * start ) ¶

int PyUnicodeEncodeError_GetStart ( PyObject * exc , Py_ssize_t * start ) ¶

int PyUnicodeTranslateError_GetStart ( PyObject * exc , Py_ssize_t * start ) ¶

属于 稳定 ABI (应用程序二进制接口) .

获取 start attribute of the given exception object and place it into *start . start 不得为 NULL 。返回 0 当成功时， -1 当故障时。

int PyUnicodeDecodeError_SetStart ( PyObject * exc , Py_ssize_t start ) ¶

int PyUnicodeEncodeError_SetStart ( PyObject * exc , Py_ssize_t start ) ¶

int PyUnicodeTranslateError_SetStart ( PyObject * exc , Py_ssize_t start ) ¶

属于 稳定 ABI (应用程序二进制接口) .

设置 start attribute of the given exception object to start 。返回 0 当成功时， -1 当故障时。

int PyUnicodeDecodeError_GetEnd ( PyObject * exc , Py_ssize_t * end ) ¶

int PyUnicodeEncodeError_GetEnd ( PyObject * exc , Py_ssize_t * end ) ¶

int PyUnicodeTranslateError_GetEnd ( PyObject * exc , Py_ssize_t * end ) ¶

属于 稳定 ABI (应用程序二进制接口) .

获取 end attribute of the given exception object and place it into *end . end 不得为 NULL 。返回 0 当成功时， -1 当故障时。

int PyUnicodeDecodeError_SetEnd ( PyObject * exc , Py_ssize_t end ) ¶

int PyUnicodeEncodeError_SetEnd ( PyObject * exc , Py_ssize_t end ) ¶

int PyUnicodeTranslateError_SetEnd ( PyObject * exc , Py_ssize_t end ) ¶

属于 稳定 ABI (应用程序二进制接口) .

设置 end attribute of the given exception object to end 。返回 0 当成功时， -1 当故障时。

PyObject * PyUnicodeDecodeError_GetReason ( PyObject * exc ) ¶

PyObject * PyUnicodeEncodeError_GetReason ( PyObject * exc ) ¶

PyObject * PyUnicodeTranslateError_GetReason ( PyObject * exc ) ¶

返回值：新引用。 属于 稳定 ABI (应用程序二进制接口) .

返回 reason 属性为给定异常对象。

int PyUnicodeDecodeError_SetReason ( PyObject * exc , const char * reason ) ¶

int PyUnicodeEncodeError_SetReason ( PyObject * exc , const char * reason ) ¶

int PyUnicodeTranslateError_SetReason ( PyObject * exc , const char * reason ) ¶

属于 稳定 ABI (应用程序二进制接口) .

设置 reason attribute of the given exception object to reason 。返回 0 当成功时， -1 当故障时。

递归控制 ¶

These two functions provide a way to perform safe recursive calls at the C level, both in the core and in extension modules. They are needed if the recursive code does not necessarily invoke Python code (which tracks its recursion depth automatically). They are also not needed for tp_call implementations because the call protocol takes care of recursion handling.

int Py_EnterRecursiveCall ( const char * where ) ¶

属于 稳定 ABI (应用程序二进制接口) since version 3.9.

Marks a point where a recursive C-level call is about to be performed.

若 USE_STACKCHECK is defined, this function checks if the OS stack overflowed using PyOS_CheckStack() . In this is the case, it sets a MemoryError and returns a nonzero value.

The function then checks if the recursion limit is reached. If this is the case, a RecursionError is set and a nonzero value is returned. Otherwise, zero is returned.

where should be a UTF-8 encoded string such as " in instance check" to be concatenated to the RecursionError message caused by the recursion depth limit.

3.9 版改变： This function is now also available in the limited API.

void Py_LeaveRecursiveCall ( void ) ¶

属于 稳定 ABI (应用程序二进制接口) since version 3.9.

Ends a Py_EnterRecursiveCall() . Must be called once for each successful invocation of Py_EnterRecursiveCall() .

3.9 版改变： This function is now also available in the limited API.

Properly implementing tp_repr for container types requires special recursion handling. In addition to protecting the stack, tp_repr also needs to track objects to prevent cycles. The following two functions facilitate this functionality. Effectively, these are the C equivalent to reprlib.recursive_repr() .

int Py_ReprEnter ( PyObject * object ) ¶

属于 稳定 ABI (应用程序二进制接口) .

Called at the beginning of the tp_repr implementation to detect cycles.

If the object has already been processed, the function returns a positive integer. In that case the tp_repr implementation should return a string object indicating a cycle. As examples, dict objects return {...} and list objects return [...] .

The function will return a negative integer if the recursion limit is reached. In that case the tp_repr implementation should typically return NULL .

Otherwise, the function returns zero and the tp_repr implementation can continue normally.

void Py_ReprLeave ( PyObject * object ) ¶

属于 稳定 ABI (应用程序二进制接口) .

Ends a Py_ReprEnter() . Must be called once for each invocation of Py_ReprEnter() 返回 0。

标准异常 ¶

All standard Python exceptions are available as global variables whose names are PyExc_ followed by the Python exception name. These have the type PyObject * ; they are all class objects. For completeness, here are all the variables:

C 名称	Python 名称	注意事项
PyExc_BaseException	BaseException	1
PyExc_Exception	Exception	1
PyExc_ArithmeticError	ArithmeticError	1
PyExc_AssertionError	AssertionError
PyExc_AttributeError	AttributeError
PyExc_BlockingIOError	BlockingIOError
PyExc_BrokenPipeError	BrokenPipeError
PyExc_BufferError	BufferError
PyExc_ChildProcessError	ChildProcessError
PyExc_ConnectionAbortedError	ConnectionAbortedError
PyExc_ConnectionError	ConnectionError
PyExc_ConnectionRefusedError	ConnectionRefusedError
PyExc_ConnectionResetError	ConnectionResetError
PyExc_EOFError	EOFError
PyExc_FileExistsError	FileExistsError
PyExc_FileNotFoundError	FileNotFoundError
PyExc_FloatingPointError	FloatingPointError
PyExc_GeneratorExit	GeneratorExit
PyExc_ImportError	ImportError
PyExc_IndentationError	IndentationError
PyExc_IndexError	IndexError
PyExc_InterruptedError	InterruptedError
PyExc_IsADirectoryError	IsADirectoryError
PyExc_KeyError	KeyError
PyExc_KeyboardInterrupt	KeyboardInterrupt
PyExc_LookupError	LookupError	1
PyExc_MemoryError	MemoryError
PyExc_ModuleNotFoundError	ModuleNotFoundError
PyExc_NameError	NameError
PyExc_NotADirectoryError	NotADirectoryError
PyExc_NotImplementedError	NotImplementedError
PyExc_OSError	OSError	1
PyExc_OverflowError	OverflowError
PyExc_PermissionError	PermissionError
PyExc_ProcessLookupError	ProcessLookupError
PyExc_RecursionError	RecursionError
PyExc_ReferenceError	ReferenceError
PyExc_RuntimeError	RuntimeError
PyExc_StopAsyncIteration	StopAsyncIteration
PyExc_StopIteration	StopIteration
PyExc_SyntaxError	SyntaxError
PyExc_SystemError	SystemError
PyExc_SystemExit	SystemExit
PyExc_TabError	TabError
PyExc_TimeoutError	TimeoutError
PyExc_TypeError	TypeError
PyExc_UnboundLocalError	UnboundLocalError
PyExc_UnicodeDecodeError	UnicodeDecodeError
PyExc_UnicodeEncodeError	UnicodeEncodeError
PyExc_UnicodeError	UnicodeError
PyExc_UnicodeTranslateError	UnicodeTranslateError
PyExc_ValueError	ValueError
PyExc_ZeroDivisionError	ZeroDivisionError

3.3 版新增： PyExc_BlockingIOError , PyExc_BrokenPipeError , PyExc_ChildProcessError , PyExc_ConnectionError , PyExc_ConnectionAbortedError , PyExc_ConnectionRefusedError , PyExc_ConnectionResetError , PyExc_FileExistsError , PyExc_FileNotFoundError , PyExc_InterruptedError , PyExc_IsADirectoryError , PyExc_NotADirectoryError , PyExc_PermissionError , PyExc_ProcessLookupError and PyExc_TimeoutError were introduced following PEP 3151 .

3.5 版新增： PyExc_StopAsyncIteration and PyExc_RecursionError .

3.6 版新增： PyExc_ModuleNotFoundError .

这些是兼容性别名化的 PyExc_OSError :

C 名称	注意事项
PyExc_EnvironmentError
PyExc_IOError
PyExc_WindowsError	2

3.3 版改变： 这些别名用于单独异常类型。

注意事项：

1 ( 1 , 2 , 3 , 4 , 5 )

This is a base class for other standard exceptions.

2

Only defined on Windows; protect code that uses this by testing that the preprocessor macro MS_WINDOWS 有定义。

标准警告类别 ¶

All standard Python warning categories are available as global variables whose names are PyExc_ followed by the Python exception name. These have the type PyObject * ; they are all class objects. For completeness, here are all the variables:

C 名称	Python 名称	注意事项
PyExc_Warning	Warning	3
PyExc_BytesWarning	BytesWarning
PyExc_DeprecationWarning	DeprecationWarning
PyExc_FutureWarning	FutureWarning
PyExc_ImportWarning	ImportWarning
PyExc_PendingDeprecationWarning	PendingDeprecationWarning
PyExc_ResourceWarning	ResourceWarning
PyExc_RuntimeWarning	RuntimeWarning
PyExc_SyntaxWarning	SyntaxWarning
PyExc_UnicodeWarning	UnicodeWarning
PyExc_UserWarning	UserWarning

3.2 版新增： PyExc_ResourceWarning .

注意事项：

3

This is a base class for other standard warning categories.

内容表

• 异常处理
  • 打印和清零
  • 引发异常
  • 发出警告
  • 查询错误指针
  • 信号处理
  • 异常类
  • 异常对象
  • Unicode 异常对象
  • 递归控制
  • 标准异常
  • 标准警告类别

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