"""
From https://docs.python.org/3.9/c-api/file.html

These APIs are a minimal emulation of the Python 2 C API for built-in file objects,
which used to rely on the buffered I/O (FILE*) support from the C standard library.
In Python 3, files and streams use the new io module, which defines several layers
over the low-level unbuffered I/O of the operating system. The functions described
below are convenience C wrappers over these new APIs, and meant mostly for internal
error reporting in the interpreter;

third-party code is advised to access the io APIs instead.
"""

cdef extern from "Python.h":

    ###########################################################################
    # File Objects
    ###########################################################################

    object PyFile_FromFd(int fd, const char *name, const char *mode, int buffering,
                         const char *encoding, const char *errors, const char *newline, int closefd)
    # Return value: New reference.
    # 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.

    # Warning: Since Python streams have their own buffering layer, mixing
    # them with OS-level file descriptors can produce various issues (such as
    # unexpected ordering of data).

    # Changed in version 3.2: Ignore name attribute.

    object PyFile_GetLine(object p, int n)
    # Return value: New reference.
    # 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_WriteObject(object obj, object p, int flags) except? -1
    # 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, object p) except? -1
    # Write string s to file object p. Return 0 on success or -1 on failure;
    # the appropriate exception will be set.

    enum: Py_PRINT_RAW