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, or "-1" se retornarem um número inteiro
(exceção: as funções "PyArg_*()" retornam "1" em caso de sucesso e "0"
em caso de 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()

   Limpe o indicador de erro. Se o indicador de erro não estiver
   definido, não haverá efeito.

void PyErr_PrintEx(int set_sys_last_vars)

   Print a standard traceback to "sys.stderr" and clear the error
   indicator. **Unless** 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" 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 variables "sys.last_type",
   "sys.last_value" and "sys.last_traceback" will be set to the type,
   value and traceback of the printed exception, respectively.

void PyErr_Print()

   Alias para``PyErr_PrintEx(1)``.

void PyErr_WriteUnraisable(PyObject *obj)

   Chame "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.

   Uma exceção deve ser definida ao chamar essa função.


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)

   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
   increment its reference count. The second argument is an error
   message; it is decoded from "'utf-8"'.

void PyErr_SetObject(PyObject *type, PyObject *value)

   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, ...)
    *Return value: Always NULL.*

   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 in "PyUnicode_FromFormat()". *format* is
   an ASCII-encoded string.

PyObject* PyErr_FormatV(PyObject *exception, const char *format, va_list vargs)
    *Return value: Always NULL.*

   Igual a "PyErr_Format()", mas usando o argumento "va_list" em vez
   de um número variável de argumentos.

   Novo na versão 3.5.

void PyErr_SetNone(PyObject *type)

   Isso é uma abreviação para "PyErr_SetObject(type, Py_None)".

int PyErr_BadArgument()

   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()
    *Return value: Always NULL.*

   Essa é uma abreviação para "PyErr_SetNone(PyExc_MemoryError)"; que
   retorna "NULL"  para que uma função de alocação de objeto possa
   escrever "return PyErr_NoMemory();"  quando ficar sem memória.

PyObject* PyErr_SetFromErrno(PyObject *type)
    *Return value: Always NULL.*

   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
   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)
    *Return value: Always NULL.*

   Similar to "PyErr_SetFromErrno()", with the additional behavior
   that if *filenameObject* is not "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)
    *Return value: Always NULL.*

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

   Novo na versão 3.4.

PyObject* PyErr_SetFromErrnoWithFilename(PyObject *type, const char *filename)
    *Return value: Always NULL.*

   Similar to "PyErr_SetFromErrnoWithFilenameObject()", but the
   filename is given as a C string.  *filename* is decoded from the
   filesystem encoding ("os.fsdecode()").

PyObject* PyErr_SetFromWindowsErr(int ierr)
    *Return value: Always NULL.*

   This is a convenience function to raise "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".

   Disponibilidade: Windows.

PyObject* PyErr_SetExcFromWindowsErr(PyObject *type, int ierr)
    *Return value: Always NULL.*

   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)
    *Return value: Always NULL.*

   Similar à "PyErr_SetFromWindowsErrWithFilenameObject()", mas o nome
   do arquivo é dados como uma String C. O nome do arquivo é
   decodificado a partir do sistema de arquivos ("os.fsdecode()").

   Disponibilidade: Windows.

PyObject* PyErr_SetExcFromWindowsErrWithFilenameObject(PyObject *type, int ierr, PyObject *filename)
    *Return value: Always NULL.*

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

   Disponibilidade: Windows.

PyObject* PyErr_SetExcFromWindowsErrWithFilenameObjects(PyObject *type, int ierr, PyObject *filename, PyObject *filename2)
    *Return value: Always NULL.*

   Similar à "PyErr_SetExcFromWindowsErrWithFilenameObject()", mas
   aceita um segundo caminho do objeto.

   Disponibilidade: Windows.

   Novo na versão 3.4.

PyObject* PyErr_SetExcFromWindowsErrWithFilename(PyObject *type, int ierr, const char *filename)
    *Return value: Always NULL.*

   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)
    *Return value: Always NULL.*

   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 be "NULL", will be set as the "ImportError"'s
   respective "name" and "path" attributes.

   Novo na versão 3.3.

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".

   Novo na versão 3.4.

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

   Like "PyErr_SyntaxLocationObject()", but *filename* is a byte
   string decoded from the filesystem encoding ("os.fsdecode()").

   Novo na versão 3.2.

void PyErr_SyntaxLocation(const char *filename, int lineno)

   Como "PyErr_SyntaxLocationEx()", mas o parâmetro col_offset é
   omitido.

void PyErr_BadInternalCall()

   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 avisos
===============

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)

   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 calling "PyErr_WarnEx()", 2 is  the function above
   that, and so forth.

   Warning categories must be subclasses of "PyExc_Warning";
   "PyExc_Warning" is a subclass of "PyExc_Exception"; the default
   warning category is "PyExc_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.

PyObject* PyErr_SetImportErrorSubclass(PyObject *exception, PyObject *msg, PyObject *name, PyObject *path)
    *Return value: Always NULL.*

   Muito parecido com "PyErr_SetImportError()" mas a função permite
   especificar uma subclasse de "ImportError" para levantar uma
   exceção.

   Novo na versão 3.6.

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.

   Novo na versão 3.4.

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

   Similar to "PyErr_WarnExplicitObject()" except that *message* and
   *module* are UTF-8 encoded strings, and *filename* is decoded from
   the filesystem encoding ("os.fsdecode()").

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

   Function similar to "PyErr_WarnEx()", but use
   "PyUnicode_FromFormat()" to format the warning message.  *format*
   is an ASCII-encoded string.

   Novo na versão 3.2.

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

   Function similar to "PyErr_WarnFormat()", but *category* is
   "ResourceWarning" and it passes *source* to
   "warnings.WarningMessage()".

   Novo na versão 3.6.


Consultando o indicador de erro
===============================

PyObject* PyErr_Occurred()
    *Return value: Borrowed reference.*

   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 to "PyErr_Restore()").  If not set,
   return "NULL".  You do not own a reference to the return value, so
   you do not need to "Py_DECREF()" it.

   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)

   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)

   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.

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

   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.

   Nota:

     Esta função, normalmente, é usada apenas pelo código que precisa
     capturar exceções ou pelo código que precisa salvar e restaurar
     temporariamente o indicador de erro. 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)

   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.)

   Nota:

     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)

   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);
        }

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

   Retrieve 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.

   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.

   Novo na versão 3.3.

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

   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, pass
   "NULL" for all three arguments. For general rules about the three
   arguments, see "PyErr_Restore()".

   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.

   Novo na versão 3.3.


Tratamento de sinal
===================

int PyErr_CheckSignals()

   This function interacts with Python's signal handling.  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.  In
   all cases, the default effect for "SIGINT" is to raise the
   "KeyboardInterrupt" exception.  If an exception is raised the error
   indicator is set and the function returns "-1"; otherwise the
   function returns "0".  The error indicator may or may not be
   cleared if it was previously set.

void PyErr_SetInterrupt()

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

   If "SIGINT" isn't handled by Python (it was set to "signal.SIG_DFL"
   or "signal.SIG_IGN"), this function does nothing.

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 à "signal.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)
    *Return value: New reference.*

   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 normally "NULL". This creates a class object derived
   from "Exception" (accessible in C as "PyExc_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)
    *Return value: New reference.*

   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.

   Novo na versão 3.2.


Objeto Exceção
==============

PyObject* PyException_GetTraceback(PyObject *ex)
    *Return value: New reference.*

   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)

   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)
    *Return value: New reference.*

   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)

   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)
    *Return value: New reference.*

   Return the cause (either an exception instance, or "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)

   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 or "None".  This steals a reference to
   *cause*.

   "__suppress_context__" para essa função é definido "True" ,
   implicitamente.


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)
    *Return value: New reference.*

   Create a "UnicodeDecodeError" object with the attributes
   *encoding*, *object*, *length*, *start*, *end* and *reason*.
   *encoding* and *reason* are UTF-8 encoded strings.

PyObject* PyUnicodeEncodeError_Create(const char *encoding, const Py_UNICODE *object, Py_ssize_t length, Py_ssize_t start, Py_ssize_t end, const char *reason)
    *Return value: New reference.*

   Create a "UnicodeEncodeError" object with the attributes
   *encoding*, *object*, *length*, *start*, *end* and *reason*.
   *encoding* and *reason* are UTF-8 encoded strings.

   Obsoleto desde a versão 3.3: 3.11"Py_UNICODE" is deprecated since
   Python 3.3. Please migrate to
   "PyObject_CallFunction(PyExc_UnicodeEncodeError, "sOnns", ...)".

PyObject* PyUnicodeTranslateError_Create(const Py_UNICODE *object, Py_ssize_t length, Py_ssize_t start, Py_ssize_t end, const char *reason)
    *Return value: New reference.*

   Create a "UnicodeTranslateError" object with the attributes
   *object*, *length*, *start*, *end* and *reason*. *reason* is a
   UTF-8 encoded string.

   Obsoleto desde a versão 3.3: 3.11"Py_UNICODE" is deprecated since
   Python 3.3. Please migrate to
   "PyObject_CallFunction(PyExc_UnicodeTranslateError, "Onns", ...)".

PyObject* PyUnicodeDecodeError_GetEncoding(PyObject *exc)
PyObject* PyUnicodeEncodeError_GetEncoding(PyObject *exc)
    *Return value: New reference.*

   Retorna o atributo * encoding* dado no objeto da exceção.

PyObject* PyUnicodeDecodeError_GetObject(PyObject *exc)
PyObject* PyUnicodeEncodeError_GetObject(PyObject *exc)
PyObject* PyUnicodeTranslateError_GetObject(PyObject *exc)
    *Return value: New reference.*

   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)

   Obtém o atributo *start* do objeto da exceção coloca-o em **start*.
   *start* não deve ser "NULL". Retorna "0" 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)

   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)

   Obtenha o atributo *end* dado no objeto de exceção e coloque
   **end*. O *end* não deve ser "NULL". Em caso de sucesso, retorna
   "0", 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)

   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)
    *Return value: New reference.*

   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)

   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).

int Py_EnterRecursiveCall(const char *where)

   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 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 string such as "" in instance check"" to be
   concatenated to the "RecursionError" message caused by the
   recursion depth limit.

void Py_LeaveRecursiveCall()

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

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)

   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 "{...}" and "list" objects return "[...]".

   A função retornará um inteiro negativo se o limite da recursão for
   atingido. Nesse caso a implementação "tp_repr" deverá,
   normalmente,. retornar "NULL".

   Caso contrário, a função retorna zero e a implementação "tp_repr"
   poderá continuar normalmente.

void Py_ReprLeave(PyObject *object)

   Termina a "Py_ReprEnter()". Deve ser chamado uma vez para cada
   chamada de "Py_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      |
|===========================================|===================================|============|
| "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"                  | (2)        |
+-------------------------------------------+-----------------------------------+------------+
| "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"               |            |
+-------------------------------------------+-----------------------------------+------------+

Novo 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" and
"PyExc_TimeoutError" were introduced following **PEP 3151**.

Novo na versão 3.5: "PyExc_StopAsyncIteration" and
"PyExc_RecursionError".

Novo na versão 3.6: "PyExc_ModuleNotFoundError".

Esses são os aliases de compatibilidade para "PyExc_OSError":

+---------------------------------------+------------+
| Nome C                                | Notas      |
|=======================================|============|
| "PyExc_EnvironmentError"              |            |
+---------------------------------------+------------+
| "PyExc_IOError"                       |            |
+---------------------------------------+------------+
| "PyExc_WindowsError"                  | (3)        |
+---------------------------------------+------------+

Alterado na versão 3.3: Esses aliases costumavam ser tipos de exceção
separados.

Notas:

1. Esta é uma classe base para outras exceções padrão.

2. Defina apenas no Windows; proteja o código que usa isso testando se
   a macro do pré-processador "MS_WINDOWS" está definida.


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      |
|============================================|===================================|============|
| "PyExc_Warning"                            | "Warning"                         | (1)        |
+--------------------------------------------+-----------------------------------+------------+
| "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"                     |            |
+--------------------------------------------+-----------------------------------+------------+

Novo na versão 3.2: "PyExc_ResourceWarning".

Notas:

1. Esta é uma classe base para outras categorias de aviso padrão.
