檔案物件 (File Objects)

這些 API 是用於內建檔案物件的 Python 2 C API 的最小模擬 (minimal emulation)，它過去依賴於 C 標準函式庫對於緩衝 I/O (FILE*) 的支援。在 Python 3 中，檔案和串流使用新的 io 模組，它在操作系統的低階無緩衝 I/O 上定義了多個層級。下面描述的函式是這些新 API 的便捷 C 包裝器，主要用於直譯器中的內部錯誤報告；建議第三方程式碼改為存取 io API。

PyObject *PyFile_FromFd(int fd, const char *name, const char *mode, int buffering, const char *encoding, const char *errors, const char *newline, int closefd)

回傳值：新的參照。 Part of the Stable ABI.

Create a Python file object from the file descriptor of an already opened file fd. The arguments name, encoding, errors and newline can be NULL to use the defaults; buffering can be -1 to use the default. name is ignored and kept for backward compatibility. Return NULL on failure. For a more comprehensive description of the arguments, please refer to the io.open() function documentation.

警告

由於 Python 串流有自己的緩衝層，將它們與操作系統層級檔案描述器混合使用會產生各種問題（例如資料的排序不符合預期）。

在 3.2 版的變更: 忽略 name 屬性。

int PyObject_AsFileDescriptor(PyObject *p)

Part of the Stable ABI.

回傳與 p 關聯的檔案描述器作為 int。如果物件是整數，則回傳其值。如果不是整數，則呼叫物件的 fileno() 方法（如果存在）；該方法必須回傳一個整數，它作為檔案描述器值回傳。設定例外並在失敗時回傳 -1。

PyObject *PyFile_GetLine(PyObject *p, int n)

回傳值：新的參照。 Part of the Stable ABI.

Equivalent to p.readline([n]), this function reads one line from the object p. p may be a file object or any object with a readline() method. If n is 0, exactly one line is read, regardless of the length of the line. If n is greater than 0, no more than n bytes will be read from the file; a partial line can be returned. In both cases, an empty string is returned if the end of the file is reached immediately. If n is less than 0, however, one line is read regardless of length, but EOFError is raised if the end of the file is reached immediately.

int PyFile_SetOpenCodeHook(Py_OpenCodeHookFunction handler)

覆蓋 io.open_code() 的正常行為以透過提供的處理程式 (handler) 傳遞其參數。

The handler is a function of type:

typedef PyObject *(*Py_OpenCodeHookFunction)(PyObject*, void*)

Equivalent of PyObject *(*)(PyObject *path, void *userData), where path is guaranteed to be PyUnicodeObject.

userData 指標被傳遞到掛鉤函式 (hook function) 中。由於可能會從不同的執行環境 (runtime) 呼叫掛鉤函式，因此該指標不應直接指向 Python 狀態。

由於此掛鉤函式是在導入期間有意使用的，因此請避免在其執行期間導入新模組，除非它們已知有被凍結或在 sys.modules 中可用。

Once a hook has been set, it cannot be removed or replaced, and later calls to PyFile_SetOpenCodeHook() will fail. On failure, the function returns -1 and sets an exception if the interpreter has been initialized.

在 Py_Initialize() 之前呼叫此函式是安全的。

不帶引數地引發一個稽核事件 (auditing event) setopencodehook。

在 3.8 版新加入.

int PyFile_WriteObject(PyObject *obj, PyObject *p, int flags)

Part of the Stable ABI.

Write object obj to file object p. The only supported flag for flags is Py_PRINT_RAW; if given, the str() of the object is written instead of the repr(). Return 0 on success or -1 on failure; the appropriate exception will be set.

int PyFile_WriteString(const char *s, PyObject *p)

Part of the Stable ABI.

寫入字串 s 到 檔案物件 p。當成功時回傳 0，而當失敗時回傳 -1，並會設定合適的例外狀況。