Class TextIOWrapper

Lib/_pyio.py:2047–2727

r"""Character and line based layer over a BufferedIOBase object, buffer. encoding gives the name of the encoding that the stream will be decoded or encoded with. It defaults to locale.getencoding(). errors determines the strictness of encoding and decoding (see the codecs.register)

class TextIOWrapper(TextIOBase):

    r"""Character and line based layer over a BufferedIOBase object, buffer.

    encoding gives the name of the encoding that the stream will be
    decoded or encoded with. It defaults to locale.getencoding().

    errors determines the strictness of encoding and decoding (see the
    codecs.register) and defaults to "strict".

    newline can be None, '', '\n', '\r', or '\r\n'.  It controls the
    handling of line endings. If it is None, universal newlines is
    enabled.  With this enabled, on input, the lines endings '\n', '\r',
    or '\r\n' are translated to '\n' before being returned to the
    caller. Conversely, on output, '\n' is translated to the system
    default line separator, os.linesep. If newline is any other of its
    legal values, that newline becomes the newline when the file is read
    and it is returned untranslated. On output, '\n' is converted to the
    newline.

    If line_buffering is True, a call to flush is implied when a call to
    write contains a newline character.
    """

    _CHUNK_SIZE = 2048

    # Initialize _buffer as soon as possible since it's used by __del__()
    # which calls close()
    _buffer = None

    # The write_through argument has no effect here since this
    # implementation always writes through.  The argument is present only
    # so that the signature can match the signature of the C version.
    def __init__(self, buffer, encoding=None, errors=None, newline=None,
                 line_buffering=False, write_through=False):
        self._check_newline(newline)
        encoding = text_encoding(encoding)

        if encoding == "locale":
            encoding = self._get_locale_encoding()

        if not isinstance(encoding, str):
            raise ValueError("invalid encoding: %r" % encoding)

        if not codecs.lookup(encoding)._is_text_encoding:
            msg = "%r is not a text encoding"
            raise LookupError(msg % encoding)

        if errors is None:
            errors = "strict"
        else:
            if not isinstance(errors, str):
                raise ValueError("invalid errors: %r" % errors)
            if _CHECK_ERRORS:
                codecs.lookup_error(errors)

        self._buffer = buffer
        self._decoded_chars = ''  # buffer for text returned from decoder