Manipulando Exceções¶
As funções descritas nesse capítulo permitem você tratar e gerar exceções em Python. É importante entender alguns princípios básicos no tratamento de exceção no Python. Funciona de forma parecida com a variável POSIX errno
: existe um indicador global (por thread) do último erro ocorrido. A maioria das funções da API C não limpa isso com êxito, mas indica a causa do erro na falha. A maioria das funções da API retorna um indicador de erro, geralmente, NULL
se eles devem retornar um ponteiro, ou -1
se retornarem um inteiro (exceção: as funções PyArg_*
retornam 1
para sucesso e 0
para falha).
Concretamente, o indicador de erro consiste em três ponteiros de objeto: o tipo da exceção, o valor da exceção e o objeto de traceback. Qualquer um desses ponteiros pode ser NULL
se não definido (embora algumas combinações sejam proibidas, por exemplo, você não pode ter um retorno não NULL
se o tipo de exceção for NULL
).
Quando uma função deve falhar porque devido à falha de alguma função que ela chamou, ela geralmente não define o indicador de erro; a função que ela chamou já o definiu. Ela é responsável por manipular o erro e limpar a exceção ou retornar após limpar todos os recursos que possui (como referências a objetos ou alocações de memória); ela não deve continuar normalmente se não estiver preparada para lidar com o erro. Se estiver retornando devido a um erro, é importante indicar ao chamador que um erro foi definido. Se o erro não for manipulado ou propagado com cuidado, chamadas adicionais para a API Python/C podem não se comportar conforme o esperado e podem falhar de maneiras misteriosas.
Nota
The error indicator is not the result of sys.exc_info()
.
The former corresponds to an exception that is not yet caught (and is
therefore still propagating), while the latter returns an exception after
it is caught (and has therefore stopped propagating).
Impressão e limpeza¶
-
void PyErr_Clear()¶
- Parte da ABI Estável.
Limpe o indicador de erro. Se o indicador de erro não estiver definido, não haverá efeito.
-
void PyErr_PrintEx(int set_sys_last_vars)¶
- Parte da ABI Estável.
Print a standard traceback to
sys.stderr
and clear the error indicator. Unless the error is aSystemExit
, in that case no traceback is printed and the Python process will exit with the error code specified by theSystemExit
instance.Chame esta função apenas quando o indicador de erro estiver definido. Caso contrário, causará um erro fatal!
If set_sys_last_vars is nonzero, the variable
sys.last_exc
is set to the printed exception. For backwards compatibility, the deprecated variablessys.last_type
,sys.last_value
andsys.last_traceback
are also set to the type, value and traceback of this exception, respectively.Alterado na versão 3.12: The setting of
sys.last_exc
was added.
-
void PyErr_Print()¶
- Parte da ABI Estável.
Apelido para
PyErr_PrintEx(1)
.
-
void PyErr_WriteUnraisable(PyObject *obj)¶
- Parte da ABI Estável.
Chama
sys.unraisablehook()
usando a exceção atual e o argumento obj.This utility function prints a warning message to
sys.stderr
when an exception has been set but it is impossible for the interpreter to actually raise the exception. It is used, for example, when an exception occurs in an__del__()
method.The function is called with a single argument obj that identifies the context in which the unraisable exception occurred. If possible, the repr of obj will be printed in the warning message. If obj is
NULL
, only the traceback is printed.Uma exceção deve ser definida ao chamar essa função.
Alterado na versão 3.4: Exibe o traceback (situação da pilha de execução). Exibe apenas o traceback se obj for
NULL
.Alterado na versão 3.8: Utiliza
sys.unraisablehook()
.
-
void PyErr_FormatUnraisable(const char *format, ...)¶
Similar to
PyErr_WriteUnraisable()
, but the format and subsequent parameters help format the warning message; they have the same meaning and values as inPyUnicode_FromFormat()
.PyErr_WriteUnraisable(obj)
is roughly equivalent toPyErr_FormatUnraisable("Exception ignored in: %R", obj)
. If format isNULL
, only the traceback is printed.Adicionado na versão 3.13.
-
void PyErr_DisplayException(PyObject *exc)¶
- Parte da ABI Estável desde a versão 3.12.
Print the standard traceback display of
exc
tosys.stderr
, including chained exceptions and notes.Adicionado na versão 3.12.
Lançando exceções¶
Essas funções ajudam a definir o indicador de erro do thread. Por conveniência, algumas dessas funções sempre retornam um ponteiro NULL
ao usar instrução com return
.
-
void PyErr_SetString(PyObject *type, const char *message)¶
- Parte da ABI Estável.
This is the most common way to set the error indicator. The first argument specifies the exception type; it is normally one of the standard exceptions, e.g.
PyExc_RuntimeError
. You need not create a new strong reference to it (e.g. withPy_INCREF()
). The second argument is an error message; it is decoded from'utf-8'
.
-
void PyErr_SetObject(PyObject *type, PyObject *value)¶
- Parte da ABI Estável.
Essa função é semelhante à
PyErr_SetString()
mas permite especificar um objeto Python arbitrário para o valor da exceção.
-
PyObject *PyErr_Format(PyObject *exception, const char *format, ...)¶
- Retorna valor: Sempre NULL. Parte da ABI Estável.
This function sets the error indicator and returns
NULL
. exception should be a Python exception class. The format and subsequent parameters help format the error message; they have the same meaning and values as inPyUnicode_FromFormat()
. format is an ASCII-encoded string.
-
PyObject *PyErr_FormatV(PyObject *exception, const char *format, va_list vargs)¶
- Retorna valor: Sempre NULL. Parte da ABI Estável desde a versão 3.5.
Igual a
PyErr_Format()
, mas usando o argumentova_list
em vez de um número variável de argumentos.Adicionado na versão 3.5.
-
void PyErr_SetNone(PyObject *type)¶
- Parte da ABI Estável.
Isso é uma abreviação para
PyErr_SetObject(type, Py_None)
.
-
int PyErr_BadArgument()¶
- Parte da ABI Estável.
This is a shorthand for
PyErr_SetString(PyExc_TypeError, message)
, where message indicates that a built-in operation was invoked with an illegal argument. It is mostly for internal use.
-
PyObject *PyErr_NoMemory()¶
- Retorna valor: Sempre NULL. Parte da ABI Estável.
Essa é uma abreviação para
PyErr_SetNone(PyExc_MemoryError)
; que retornaNULL
para que uma função de alocação de objeto possa escreverreturn PyErr_NoMemory();
quando ficar sem memória.
-
PyObject *PyErr_SetFromErrno(PyObject *type)¶
- Retorna valor: Sempre NULL. Parte da ABI Estável.
This is a convenience function to raise an exception when a C library function has returned an error and set the C variable
errno
. It constructs a tuple object whose first item is the integererrno
value and whose second item is the corresponding error message (gotten fromstrerror()
), and then callsPyErr_SetObject(type, object)
. On Unix, when theerrno
value isEINTR
, indicating an interrupted system call, this callsPyErr_CheckSignals()
, and if that set the error indicator, leaves it set to that. The function always returnsNULL
, so a wrapper function around a system call can writereturn PyErr_SetFromErrno(type);
when the system call returns an error.
-
PyObject *PyErr_SetFromErrnoWithFilenameObject(PyObject *type, PyObject *filenameObject)¶
- Retorna valor: Sempre NULL. Parte da ABI Estável.
Similar to
PyErr_SetFromErrno()
, with the additional behavior that if filenameObject is notNULL
, it is passed to the constructor of type as a third parameter. In the case ofOSError
exception, this is used to define thefilename
attribute of the exception instance.
-
PyObject *PyErr_SetFromErrnoWithFilenameObjects(PyObject *type, PyObject *filenameObject, PyObject *filenameObject2)¶
- Retorna valor: Sempre NULL. Parte da ABI Estável desde a versão 3.7.
Similar to
PyErr_SetFromErrnoWithFilenameObject()
, but takes a second filename object, for raising errors when a function that takes two filenames fails.Adicionado na versão 3.4.
-
PyObject *PyErr_SetFromErrnoWithFilename(PyObject *type, const char *filename)¶
- Retorna valor: Sempre NULL. Parte da ABI Estável.
Similar to
PyErr_SetFromErrnoWithFilenameObject()
, but the filename is given as a C string. filename is decoded from the filesystem encoding and error handler.
-
PyObject *PyErr_SetFromWindowsErr(int ierr)¶
- Retorna valor: Sempre NULL. Parte da ABI Estável on Windows desde a versão 3.7.
This is a convenience function to raise
OSError
. If called with ierr of0
, the error code returned by a call toGetLastError()
is used instead. It calls the Win32 functionFormatMessage()
to retrieve the Windows description of error code given by ierr orGetLastError()
, then it constructs aOSError
object with thewinerror
attribute set to the error code, thestrerror
attribute set to the corresponding error message (gotten fromFormatMessage()
), and then callsPyErr_SetObject(PyExc_OSError, object)
. This function always returnsNULL
.Disponibilidade: Windows.
-
PyObject *PyErr_SetExcFromWindowsErr(PyObject *type, int ierr)¶
- Retorna valor: Sempre NULL. Parte da ABI Estável on Windows desde a versão 3.7.
Similar to
PyErr_SetFromWindowsErr()
, with an additional parameter specifying the exception type to be raised.Disponibilidade: Windows.
-
PyObject *PyErr_SetFromWindowsErrWithFilename(int ierr, const char *filename)¶
- Retorna valor: Sempre NULL. Parte da ABI Estável on Windows desde a versão 3.7.
Similar to
PyErr_SetFromWindowsErr()
, with the additional behavior that if filename is notNULL
, it is decoded from the filesystem encoding (os.fsdecode()
) and passed to the constructor ofOSError
as a third parameter to be used to define thefilename
attribute of the exception instance.Disponibilidade: Windows.
-
PyObject *PyErr_SetExcFromWindowsErrWithFilenameObject(PyObject *type, int ierr, PyObject *filename)¶
- Retorna valor: Sempre NULL. Parte da ABI Estável on Windows desde a versão 3.7.
Similar to
PyErr_SetExcFromWindowsErr()
, with the additional behavior that if filename is notNULL
, it is passed to the constructor ofOSError
as a third parameter to be used to define thefilename
attribute of the exception instance.Disponibilidade: Windows.
-
PyObject *PyErr_SetExcFromWindowsErrWithFilenameObjects(PyObject *type, int ierr, PyObject *filename, PyObject *filename2)¶
- Retorna valor: Sempre NULL. Parte da ABI Estável on Windows desde a versão 3.7.
Similar à
PyErr_SetExcFromWindowsErrWithFilenameObject()
, mas aceita um segundo caminho do objeto.Disponibilidade: Windows.
Adicionado na versão 3.4.
-
PyObject *PyErr_SetExcFromWindowsErrWithFilename(PyObject *type, int ierr, const char *filename)¶
- Retorna valor: Sempre NULL. Parte da ABI Estável on Windows desde a versão 3.7.
Similar à
PyErr_SetFromWindowsErrWithFilename()
, com um parâmetro adicional especificando o tipo de exceção a ser gerado.Disponibilidade: Windows.
-
PyObject *PyErr_SetImportError(PyObject *msg, PyObject *name, PyObject *path)¶
- Retorna valor: Sempre NULL. Parte da ABI Estável desde a versão 3.7.
This is a convenience function to raise
ImportError
. msg will be set as the exception’s message string. name and path, both of which can beNULL
, will be set as theImportError
’s respectivename
andpath
attributes.Adicionado na versão 3.3.
-
PyObject *PyErr_SetImportErrorSubclass(PyObject *exception, PyObject *msg, PyObject *name, PyObject *path)¶
- Retorna valor: Sempre NULL. Parte da ABI Estável desde a versão 3.6.
Muito parecido com
PyErr_SetImportError()
mas a função permite especificar uma subclasse deImportError
para levantar uma exceção.Adicionado na versão 3.6.
-
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 aSyntaxError
.Adicionado na versão 3.4.
-
void PyErr_SyntaxLocationEx(const char *filename, int lineno, int col_offset)¶
- Parte da ABI Estável desde a versão 3.7.
Like
PyErr_SyntaxLocationObject()
, but filename is a byte string decoded from the filesystem encoding and error handler.Adicionado na versão 3.2.
-
void PyErr_SyntaxLocation(const char *filename, int lineno)¶
- Parte da ABI Estável.
Like
PyErr_SyntaxLocationEx()
, but the col_offset parameter is omitted.
-
void PyErr_BadInternalCall()¶
- Parte da ABI Estável.
This is a shorthand for
PyErr_SetString(PyExc_SystemError, message)
, where 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.
Emitindo advertências¶
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)¶
- Parte da ABI Estável.
Issue a warning message. The category argument is a warning category (see below) or
NULL
; the 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 callingPyErr_WarnEx()
, 2 is the function above that, and so forth.Warning categories must be subclasses of
PyExc_Warning
;PyExc_Warning
is a subclass ofPyExc_Exception
; the default warning category isPyExc_RuntimeWarning
. The standard Python warning categories are available as global variables whose names are enumerated at Categorias de aviso padrão.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 toNULL
to get the default effect described there.Adicionado na versão 3.4.
-
int PyErr_WarnExplicit(PyObject *category, const char *message, const char *filename, int lineno, const char *module, PyObject *registry)¶
- Parte da ABI Estável.
Similar to
PyErr_WarnExplicitObject()
except that message and module are UTF-8 encoded strings, and filename is decoded from the filesystem encoding and error handler.
-
int PyErr_WarnFormat(PyObject *category, Py_ssize_t stack_level, const char *format, ...)¶
- Parte da ABI Estável.
Function similar to
PyErr_WarnEx()
, but usePyUnicode_FromFormat()
to format the warning message. format is an ASCII-encoded string.Adicionado na versão 3.2.
-
int PyErr_ResourceWarning(PyObject *source, Py_ssize_t stack_level, const char *format, ...)¶
- Parte da ABI Estável desde a versão 3.6.
Function similar to
PyErr_WarnFormat()
, but category isResourceWarning
and it passes source towarnings.WarningMessage
.Adicionado na versão 3.6.
Consultando o indicador de erro¶
-
PyObject *PyErr_Occurred()¶
- Retorna valor: Referência emprestada. Parte da ABI Estável.
Test whether the error indicator is set. If set, return the exception type (the first argument to the last call to one of the
PyErr_Set*
functions or toPyErr_Restore()
). If not set, returnNULL
. You do not own a reference to the return value, so you do not need toPy_DECREF()
it.The caller must hold the GIL.
Nota
Do not compare the return value to a specific exception; use
PyErr_ExceptionMatches()
instead, shown below. (The comparison could easily fail since the exception may be an instance instead of a class, in the case of a class exception, or it may be a subclass of the expected exception.)
-
int PyErr_ExceptionMatches(PyObject *exc)¶
- Parte da ABI Estável.
Equivalent to
PyErr_GivenExceptionMatches(PyErr_Occurred(), exc)
. This should only be called when an exception is actually set; a memory access violation will occur if no exception has been raised.
-
int PyErr_GivenExceptionMatches(PyObject *given, PyObject *exc)¶
- Parte da ABI Estável.
Return true if the given exception matches the exception type in exc. If exc is a class object, this also returns true when given is an instance of a subclass. If exc is a tuple, all exception types in the tuple (and recursively in subtuples) are searched for a match.
-
PyObject *PyErr_GetRaisedException(void)¶
- Retorna valor: Nova referência. Parte da ABI Estável desde a versão 3.12.
Return the exception currently being raised, clearing the error indicator at the same time. Return
NULL
if the error indicator is not set.This function is used by code that needs to catch exceptions, or code that needs to save and restore the error indicator temporarily.
Por exemplo:
{ PyObject *exc = PyErr_GetRaisedException(); /* ... code that might produce other errors ... */ PyErr_SetRaisedException(exc); }
Ver também
PyErr_GetHandledException()
, to save the exception currently being handled.Adicionado na versão 3.12.
-
void PyErr_SetRaisedException(PyObject *exc)¶
- Parte da ABI Estável desde a versão 3.12.
Set exc as the exception currently being raised, clearing the existing exception if one is set.
Aviso
This call steals a reference to exc, which must be a valid exception.
Adicionado na versão 3.12.
-
void PyErr_Fetch(PyObject **ptype, PyObject **pvalue, PyObject **ptraceback)¶
- Parte da ABI Estável.
Obsoleto desde a versão 3.12: Use
PyErr_GetRaisedException()
instead.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 beNULL
even when the type object is not.Nota
This function is normally only used by legacy code that needs to catch exceptions or save and restore the error indicator temporarily.
Por exemplo:
{ 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)¶
- Parte da ABI Estável.
Obsoleto desde a versão 3.12: Use
PyErr_SetRaisedException()
instead.Set the error indicator from the three objects, type, value, and traceback, clearing the existing exception if one is set. If the objects are
NULL
, the error indicator is cleared. Do not pass aNULL
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.)Nota
This function is normally only used by legacy 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)¶
- Parte da ABI Estável.
Obsoleto desde a versão 3.12: Use
PyErr_GetRaisedException()
instead, to avoid any possible de-normalization.Under certain circumstances, the values returned by
PyErr_Fetch()
below can be “unnormalized”, meaning that*exc
is a class object but*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.Nota
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)¶
- Parte da ABI Estável desde a versão 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 orNULL
. Does not modify the interpreter’s exception state.Nota
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.Adicionado na versão 3.11.
-
void PyErr_SetHandledException(PyObject *exc)¶
- Parte da ABI Estável desde a versão 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, passNULL
.Nota
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.Adicionado na versão 3.11.
-
void PyErr_GetExcInfo(PyObject **ptype, PyObject **pvalue, PyObject **ptraceback)¶
- Parte da ABI Estável desde a versão 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 beNULL
. Does not modify the exception info state. This function is kept for backwards compatibility. Prefer usingPyErr_GetHandledException()
.Nota
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.Adicionado na versão 3.3.
-
void PyErr_SetExcInfo(PyObject *type, PyObject *value, PyObject *traceback)¶
- Parte da ABI Estável desde a versão 3.7.
Set 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. This function steals the references of the arguments. To clear the exception state, passNULL
for all three arguments. This function is kept for backwards compatibility. Prefer usingPyErr_SetHandledException()
.Nota
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.Adicionado na versão 3.3.
Alterado na versão 3.11: The
type
andtraceback
arguments are no longer used and can be NULL. The interpreter now derives them from the exception instance (thevalue
argument). The function still steals references of all three arguments.
Tratamento de sinal¶
-
int PyErr_CheckSignals()¶
- Parte da ABI Estável.
Essa função interage com o manipulador de sinais do Python.
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 nextPyErr_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).
Nota
The default Python signal handler for
SIGINT
raises theKeyboardInterrupt
exception.
-
void PyErr_SetInterrupt()¶
- Parte da ABI Estável.
Simulate the effect of a
SIGINT
signal arriving. This is equivalent toPyErr_SetInterruptEx(SIGINT)
.Nota
This function is async-signal-safe. It can be called without the GIL and from a C signal handler.
-
int PyErr_SetInterruptEx(int signum)¶
- Parte da ABI Estável desde a versão 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).
If the given signal isn’t handled by Python (it was set to
signal.SIG_DFL
orsignal.SIG_IGN
), it will be ignored.If 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.Nota
This function is async-signal-safe. It can be called without the GIL and from a C signal handler.
Adicionado na versão 3.10.
-
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.
O valor
-1
desabilita o recurso; este é o estado inicial. Isso é equivalente àsignal.set_wakeup_fd()
em Python, mas sem nenhuma verificação de erro. fd deve ser um descritor de arquivo válido. A função só deve ser chamada a partir da thread principal.Alterado na versão 3.5: No Windows, a função agora também suporta manipuladores de socket.
Classes de exceção¶
-
PyObject *PyErr_NewException(const char *name, PyObject *base, PyObject *dict)¶
- Retorna valor: Nova referência. Parte da ABI Estável.
This utility function creates and returns a new exception class. The name argument must be the name of the new exception, a C string of the form
module.classname
. The base and dict arguments are normallyNULL
. This creates a class object derived fromException
(accessible in C asPyExc_Exception
).The
__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)¶
- Retorna valor: Nova referência. Parte da ABI Estável.
Same as
PyErr_NewException()
, except that the new exception class can easily be given a docstring: If doc is non-NULL
, it will be used as the docstring for the exception class.Adicionado na versão 3.2.
Objeto Exceção¶
-
PyObject *PyException_GetTraceback(PyObject *ex)¶
- Retorna valor: Nova referência. Parte da ABI Estável.
Return the traceback associated with the exception as a new reference, as accessible from Python through the
__traceback__
attribute. If there is no traceback associated, this returnsNULL
.
-
int PyException_SetTraceback(PyObject *ex, PyObject *tb)¶
- Parte da ABI Estável.
Defina o retorno traceback (situação da pilha de execução) associado à exceção como tb. Use
Py_None
para limpá-lo.
-
PyObject *PyException_GetContext(PyObject *ex)¶
- Retorna valor: Nova referência. Parte da ABI Estável.
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 the
__context__
attribute. If there is no context associated, this returnsNULL
.
-
void PyException_SetContext(PyObject *ex, PyObject *ctx)¶
- Parte da ABI Estável.
Set the context associated with the exception to ctx. Use
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)¶
- Retorna valor: Nova referência. Parte da ABI Estável.
Return the cause (either an exception instance, or
None
, set byraise ... from ...
) associated with the exception as a new reference, as accessible from Python through the__cause__
attribute.
-
void PyException_SetCause(PyObject *ex, PyObject *cause)¶
- Parte da ABI Estável.
Set the cause associated with the exception to cause. Use
NULL
to clear it. There is no type check to make sure that cause is either an exception instance orNone
. This steals a reference to cause.The
__suppress_context__
attribute is implicitly set toTrue
by this function.
-
PyObject *PyException_GetArgs(PyObject *ex)¶
- Retorna valor: Nova referência. Parte da ABI Estável desde a versão 3.12.
Return
args
of exception ex.
-
void PyException_SetArgs(PyObject *ex, PyObject *args)¶
- Parte da ABI Estável desde a versão 3.12.
Set
args
of exception ex to args.
-
PyObject *PyUnstable_Exc_PrepReraiseStar(PyObject *orig, PyObject *excs)¶
- Esta é uma API Instável. Isso pode se alterado sem aviso em lançamentos menores.
Implement part of the interpreter’s implementation of
except*
. orig is the original exception that was caught, and excs is the list of the exceptions that need to be raised. This list contains the unhandled part of orig, if any, as well as the exceptions that were raised from theexcept*
clauses (so they have a different traceback from orig) and those that were reraised (and have the same traceback as orig). Return theExceptionGroup
that needs to be reraised in the end, orNone
if there is nothing to reraise.Adicionado na versão 3.12.
Objetos de exceção Unicode¶
As seguintes funções são usadas para criar e modificar exceções Unicode de 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)¶
- Retorna valor: Nova referência. Parte da ABI Estável.
Create a
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)¶
- Retorna valor: Nova referência. Parte da ABI Estável.
Retorna o atributo * encoding* dado no objeto da exceção.
-
PyObject *PyUnicodeDecodeError_GetObject(PyObject *exc)¶
-
PyObject *PyUnicodeEncodeError_GetObject(PyObject *exc)¶
-
PyObject *PyUnicodeTranslateError_GetObject(PyObject *exc)¶
- Retorna valor: Nova referência. Parte da ABI Estável.
Retorna o atributo object dado no objeto da exceção.
-
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)¶
- Parte da ABI Estável.
Obtém o atributo start do objeto da exceção coloca-o em *start. start não deve ser
NULL
. Retorna0
se não der erro,-1
caso dê erro.
-
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)¶
- Parte da ABI Estável.
Define o atributo start dado no objeto de exceção start. Em caso de sucesso, retorna
0
, em caso de falha, retorna-1
.
-
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)¶
- Parte da ABI Estável.
Obtenha o atributo end dado no objeto de exceção e coloque *end. O end não deve ser
NULL
. Em caso de sucesso, retorna0
, em caso de falha, retorna-1
.
-
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)¶
- Parte da ABI Estável.
Set the end attribute of the given exception object to end. Return
0
on success,-1
on failure.
-
PyObject *PyUnicodeDecodeError_GetReason(PyObject *exc)¶
-
PyObject *PyUnicodeEncodeError_GetReason(PyObject *exc)¶
-
PyObject *PyUnicodeTranslateError_GetReason(PyObject *exc)¶
- Retorna valor: Nova referência. Parte da ABI Estável.
Retorna o atributo reason dado no objeto da exceção.
-
int PyUnicodeDecodeError_SetReason(PyObject *exc, const char *reason)¶
-
int PyUnicodeEncodeError_SetReason(PyObject *exc, const char *reason)¶
-
int PyUnicodeTranslateError_SetReason(PyObject *exc, const char *reason)¶
- Parte da ABI Estável.
Set the reason attribute of the given exception object to reason. Return
0
on success,-1
on failure.
Controle de recursão¶
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)¶
- Parte da ABI Estável desde a versão 3.9.
Marca um ponto em que a chamada recursiva em nível C está prestes a ser executada.
If
USE_STACKCHECK
is defined, this function checks if the OS stack overflowed usingPyOS_CheckStack()
. If this is the case, it sets aMemoryError
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 theRecursionError
message caused by the recursion depth limit.Alterado na versão 3.9: This function is now also available in the limited API.
-
void Py_LeaveRecursiveCall(void)¶
- Parte da ABI Estável desde a versão 3.9.
Ends a
Py_EnterRecursiveCall()
. Must be called once for each successful invocation ofPy_EnterRecursiveCall()
.Alterado na versão 3.9: 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)¶
- Parte da ABI Estável.
Chamado no início da implementação
tp_repr
para detectar ciclos.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{...}
andlist
objects return[...]
.A função retornará um inteiro negativo se o limite da recursão for atingido. Nesse caso a implementação
tp_repr
deverá, normalmente,. retornarNULL
.Caso contrário, a função retorna zero e a implementação
tp_repr
poderá continuar normalmente.
-
void Py_ReprLeave(PyObject *object)¶
- Parte da ABI Estável.
Termina a
Py_ReprEnter()
. Deve ser chamado uma vez para cada chamada dePy_ReprEnter()
que retorna zero.
Exceções Padrão¶
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:
Nome C |
Nome Python |
Notas |
---|---|---|
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
Adicionado na versão 3.3: 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
e PyExc_TimeoutError
foram introduzidos seguindo a PEP 3151.
Adicionado na versão 3.5: PyExc_StopAsyncIteration
e PyExc_RecursionError
.
Adicionado na versão 3.6: PyExc_ModuleNotFoundError
.
Esses são os aliases de compatibilidade para PyExc_OSError
:
Nome C |
Notas |
---|---|
|
|
|
|
|
Alterado na versão 3.3: Esses aliases costumavam ser tipos de exceção separados.
Notas:
Categorias de aviso padrão¶
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:
Nome C |
Nome Python |
Notas |
---|---|---|
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
Adicionado na versão 3.2: PyExc_ResourceWarning
.
Notas:
Esta é uma classe base para outras categorias de aviso padrão.