_io

The io module provides the Python interfaces to stream handling. The
builtin open function is defined in this module.

At the top of the I/O hierarchy is the abstract base class IOBase. It
defines the basic interface to a stream. Note, however, that there is no
separation between reading and writing to streams; implementations are
allowed to raise an OSError if they do not support a given operation.

Extending IOBase is RawIOBase which deals simply with the reading and
writing of raw bytes to a stream. FileIO subclasses RawIOBase to provide
an interface to OS files.

BufferedIOBase deals with buffering on a raw byte stream (RawIOBase). Its
subclasses, BufferedWriter, BufferedReader, and BufferedRWPair buffer
streams that are readable, writable, and both respectively.
BufferedRandom provides a buffered interface to random access
streams. BytesIO is a simple stream of in-memory bytes.

Another IOBase subclass, TextIOBase, deals with the encoding and decoding
of streams into text. TextIOWrapper, which extends it, is a buffered text
interface to a buffered raw stream (`BufferedIOBase`). Finally, StringIO
is an in-memory stream for text.

Argument names are not part of the specification, and only the arguments
of open() are intended to be used as keyword arguments.

data:

DEFAULT_BUFFER_SIZE

   An int containing the default buffer size used by the module's buffered
   I/O classes. open() uses the file's blksize (as obtained by os.stat) if
   possible.

Classes

BlockingIOError

I/O operation would block.

with_traceback(...)

  Exception.with_traceback(tb) --
      set self.__traceback__ to tb and return self.

args = <attribute 'args' of 'BaseException' objects>

characters_written = <attribute 'characters_written' of 'OSError' objects>

errno = <member 'errno' of 'OSError' objects>
  POSIX exception code

filename = <member 'filename' of 'OSError' objects>
  exception filename

filename2 = <member 'filename2' of 'OSError' objects>
  second exception filename

strerror = <member 'strerror' of 'OSError' objects>
  exception strerror

BufferedRWPair

A buffered reader and writer object together.

A buffered reader object and buffered writer object put together to
form a sequential IO object that can read and write. This is typically
used with a socket or two-way pipe.

reader and writer are RawIOBase objects that are readable and
writeable respectively. If the buffer_size is omitted it defaults to
DEFAULT_BUFFER_SIZE.

close(...)

detach(self, /)

  Disconnect this buffer from its underlying raw stream and return it.

  After the raw stream has been detached, the buffer is in an unusable
  state.

fileno(self, /)

  Returns underlying file descriptor if one exists.

  OSError is raised if the IO object does not use a file descriptor.

flush(...)

isatty(...)

peek(...)

read(...)

read1(...)

readable(...)

readinto(...)

readinto1(...)

readline(self, size=-1, /)

  Read and return a line from the stream.

  If size is specified, at most size bytes will be read.

  The line terminator is always b'\n' for binary files; for text
  files, the newlines argument to open can be used to select the line
  terminator(s) recognized.

readlines(self, hint=-1, /)

  Return a list of lines from the stream.

  hint can be specified to control the number of lines read: no more
  lines will be read if the total size (in bytes/characters) of all
  lines so far exceeds hint.

seek(...)

  Change stream position.

  Change the stream position to the given byte offset. The offset is
  interpreted relative to the position indicated by whence.  Values
  for whence are:

  * 0 -- start of stream (the default); offset should be zero or positive
  * 1 -- current stream position; offset may be negative
  * 2 -- end of stream; offset is usually negative

  Return the new absolute position.

seekable(self, /)

  Return whether object supports random access.

  If False, seek(), tell() and truncate() will raise OSError.
  This method may need to do a test seek().

tell(self, /)

  Return current stream position.

truncate(...)

  Truncate file to size bytes.

  File pointer is left unchanged.  Size defaults to the current IO
  position as reported by tell().  Returns the new size.

writable(...)

write(...)

writelines(self, lines, /)

  Write a list of lines to stream.

  Line separators are not added, so it is usual for each of the
  lines provided to have a line separator at the end.

closed = <attribute 'closed' of '_io.BufferedRWPair' objects>

BufferedRandom

A buffered interface to random access streams.

The constructor creates a reader and writer for a seekable stream,
raw, given in the first argument. If the buffer_size is omitted it
defaults to DEFAULT_BUFFER_SIZE.

close(...)

detach(...)

fileno(...)

flush(...)

isatty(...)

peek(self, size=0, /)

read(self, size=-1, /)

read1(self, size=-1, /)

readable(...)

readinto(self, buffer, /)

readinto1(self, buffer, /)

readline(self, size=-1, /)

readlines(self, hint=-1, /)

  Return a list of lines from the stream.

  hint can be specified to control the number of lines read: no more
  lines will be read if the total size (in bytes/characters) of all
  lines so far exceeds hint.

seek(self, target, whence=0, /)

seekable(...)

tell(...)

truncate(self, pos=None, /)

writable(...)

write(self, buffer, /)

writelines(self, lines, /)

  Write a list of lines to stream.

  Line separators are not added, so it is usual for each of the
  lines provided to have a line separator at the end.

closed = <attribute 'closed' of '_io.BufferedRandom' objects>

mode = <attribute 'mode' of '_io.BufferedRandom' objects>

name = <attribute 'name' of '_io.BufferedRandom' objects>

raw = <member 'raw' of '_io.BufferedRandom' objects>

BufferedReader

Create a new buffered reader using the given readable raw IO object.

close(...)

detach(...)

fileno(...)

flush(...)

isatty(...)

peek(self, size=0, /)

read(self, size=-1, /)

read1(self, size=-1, /)

readable(...)

readinto(self, buffer, /)

readinto1(self, buffer, /)

readline(self, size=-1, /)

readlines(self, hint=-1, /)

  Return a list of lines from the stream.

  hint can be specified to control the number of lines read: no more
  lines will be read if the total size (in bytes/characters) of all
  lines so far exceeds hint.

seek(self, target, whence=0, /)

seekable(...)

tell(...)

truncate(self, pos=None, /)

writable(self, /)

  Return whether object was opened for writing.

  If False, write() will raise OSError.

write(...)

  Write the given buffer to the IO stream.

  Returns the number of bytes written, which is always the length of b
  in bytes.

  Raises BlockingIOError if the buffer is full and the
  underlying raw stream cannot accept more data at the moment.

writelines(self, lines, /)

  Write a list of lines to stream.

  Line separators are not added, so it is usual for each of the
  lines provided to have a line separator at the end.

closed = <attribute 'closed' of '_io.BufferedReader' objects>

mode = <attribute 'mode' of '_io.BufferedReader' objects>

name = <attribute 'name' of '_io.BufferedReader' objects>

raw = <member 'raw' of '_io.BufferedReader' objects>

BufferedWriter

A buffer for a writeable sequential RawIO object.

The constructor creates a BufferedWriter for the given writeable raw
stream. If the buffer_size is not given, it defaults to
DEFAULT_BUFFER_SIZE.

close(...)

detach(...)

fileno(...)

flush(...)

isatty(...)

read(...)

  Read and return up to n bytes.

  If the argument is omitted, None, or negative, reads and
  returns all data until EOF.

  If the argument is positive, and the underlying raw stream is
  not 'interactive', multiple raw reads may be issued to satisfy
  the byte count (unless EOF is reached first).  But for
  interactive raw streams (as well as sockets and pipes), at most
  one raw read will be issued, and a short result does not imply
  that EOF is imminent.

  Returns an empty bytes object on EOF.

  Returns None if the underlying raw stream was open in non-blocking
  mode and no data is available at the moment.

read1(...)

  Read and return up to n bytes, with at most one read() call
  to the underlying raw stream. A short result does not imply
  that EOF is imminent.

  Returns an empty bytes object on EOF.

readable(self, /)

  Return whether object was opened for reading.

  If False, read() will raise OSError.

readinto(self, buffer, /)

readinto1(self, buffer, /)

readline(self, size=-1, /)

  Read and return a line from the stream.

  If size is specified, at most size bytes will be read.

  The line terminator is always b'\n' for binary files; for text
  files, the newlines argument to open can be used to select the line
  terminator(s) recognized.

readlines(self, hint=-1, /)

  Return a list of lines from the stream.

  hint can be specified to control the number of lines read: no more
  lines will be read if the total size (in bytes/characters) of all
  lines so far exceeds hint.

seek(self, target, whence=0, /)

seekable(...)

tell(...)

truncate(self, pos=None, /)

writable(...)

write(self, buffer, /)

writelines(self, lines, /)

  Write a list of lines to stream.

  Line separators are not added, so it is usual for each of the
  lines provided to have a line separator at the end.

closed = <attribute 'closed' of '_io.BufferedWriter' objects>

mode = <attribute 'mode' of '_io.BufferedWriter' objects>

name = <attribute 'name' of '_io.BufferedWriter' objects>

raw = <member 'raw' of '_io.BufferedWriter' objects>

BytesIO

Buffered I/O implementation using an in-memory bytes buffer.

close(self, /)

  Disable all I/O operations.

detach(self, /)

  Disconnect this buffer from its underlying raw stream and return it.

  After the raw stream has been detached, the buffer is in an unusable
  state.

fileno(self, /)

  Returns underlying file descriptor if one exists.

  OSError is raised if the IO object does not use a file descriptor.

flush(self, /)

  Does nothing.

getbuffer(self, /)

  Get a read-write view over the contents of the BytesIO object.

getvalue(self, /)

  Retrieve the entire contents of the BytesIO object.

isatty(self, /)

  Always returns False.

  BytesIO objects are not connected to a TTY-like device.

read(self, size=-1, /)

  Read at most size bytes, returned as a bytes object.

  If the size argument is negative, read until EOF is reached.
  Return an empty bytes object at EOF.

read1(self, size=-1, /)

  Read at most size bytes, returned as a bytes object.

  If the size argument is negative or omitted, read until EOF is reached.
  Return an empty bytes object at EOF.

readable(self, /)

  Returns True if the IO object can be read.

readinto(self, buffer, /)

  Read bytes into buffer.

  Returns number of bytes read (0 for EOF), or None if the object
  is set not to block and has no data to read.

readinto1(self, buffer, /)

readline(self, size=-1, /)

  Next line from the file, as a bytes object.

  Retain newline.  A non-negative size argument limits the maximum
  number of bytes to return (an incomplete line may be returned then).
  Return an empty bytes object at EOF.

readlines(self, size=None, /)

  List of bytes objects, each a line from the file.

  Call readline() repeatedly and return a list of the lines so read.
  The optional size argument, if given, is an approximate bound on the
  total number of bytes in the lines returned.

seek(self, pos, whence=0, /)

  Change stream position.

  Seek to byte offset pos relative to position indicated by whence:
       0  Start of stream (the default).  pos should be >= 0;
       1  Current position - pos may be negative;
       2  End of stream - pos usually negative.
  Returns the new absolute position.

seekable(self, /)

  Returns True if the IO object can be seeked.

tell(self, /)

  Current file position, an integer.

truncate(self, size=None, /)

  Truncate the file to at most size bytes.

  Size defaults to the current file position, as returned by tell().
  The current file position is unchanged.  Returns the new size.

writable(self, /)

  Returns True if the IO object can be written.

write(self, b, /)

  Write bytes to file.

  Return the number of bytes written.

writelines(self, lines, /)

  Write lines to the file.

  Note that newlines are not added.  lines can be any iterable object
  producing bytes-like objects. This is equivalent to calling write() for
  each element.

closed = <attribute 'closed' of '_io.BytesIO' objects>
  True if the file is closed.

FileIO

Open a file.

The mode can be 'r' (default), 'w', 'x' or 'a' for reading,
writing, exclusive creation or appending.  The file will be created if it
doesn't exist when opened for writing or appending; it will be truncated
when opened for writing.  A FileExistsError will be raised if it already
exists when opened for creating. Opening a file for creating implies
writing so this mode behaves in a similar way to 'w'.Add a '+' to the mode
to allow simultaneous reading and writing. A custom opener can be used by
passing a callable as *opener*. The underlying file descriptor for the file
object is then obtained by calling opener with (*name*, *flags*).

	opener* must return an open file descriptor (passing os.open as *opener*

results in functionality similar to passing None).

close(self, /)

  Close the file.

  A closed file cannot be used for further I/O operations.  close() may be
  called more than once without error.

fileno(self, /)

  Return the underlying file descriptor (an integer).

flush(self, /)

  Flush write buffers, if applicable.

  This is not implemented for read-only and non-blocking streams.

isatty(self, /)

  True if the file is connected to a TTY device.

read(self, size=-1, /)

  Read at most size bytes, returned as bytes.

  Only makes one system call, so less data may be returned than requested.
  In non-blocking mode, returns None if no data is available.
  Return an empty bytes object at EOF.

readable(self, /)

  True if file was opened in a read mode.

readall(self, /)

  Read all data from the file, returned as bytes.

  In non-blocking mode, returns as much as is immediately available,
  or None if no data is available.  Return an empty bytes object at EOF.

readinto(self, buffer, /)

  Same as RawIOBase.readinto().

readline(self, size=-1, /)

  Read and return a line from the stream.

  If size is specified, at most size bytes will be read.

  The line terminator is always b'\n' for binary files; for text
  files, the newlines argument to open can be used to select the line
  terminator(s) recognized.

readlines(self, hint=-1, /)

  Return a list of lines from the stream.

  hint can be specified to control the number of lines read: no more
  lines will be read if the total size (in bytes/characters) of all
  lines so far exceeds hint.

seek(self, pos, whence=0, /)

  Move to new file position and return the file position.

  Argument offset is a byte count.  Optional argument whence defaults to
  SEEK_SET or 0 (offset from start of file, offset should be >= 0); other values
  are SEEK_CUR or 1 (move relative to current position, positive or negative),
  and SEEK_END or 2 (move relative to end of file, usually negative, although
  many platforms allow seeking beyond the end of a file).

  Note that not all file objects are seekable.

seekable(self, /)

  True if file supports random-access.

tell(self, /)

  Current file position.

  Can raise OSError for non seekable files.

truncate(self, size=None, /)

  Truncate the file to at most size bytes and return the truncated size.

  Size defaults to the current file position, as returned by tell().
  The current file position is changed to the value of size.

writable(self, /)

  True if file was opened in a write mode.

write(self, b, /)

  Write buffer b to file, return number of bytes written.

  Only makes one system call, so not all of the data may be written.
  The number of bytes actually written is returned.  In non-blocking mode,
  returns None if the write would block.

writelines(self, lines, /)

  Write a list of lines to stream.

  Line separators are not added, so it is usual for each of the
  lines provided to have a line separator at the end.

closed = <attribute 'closed' of '_io.FileIO' objects>
  True if the file is closed

closefd = <attribute 'closefd' of '_io.FileIO' objects>
  True if the file descriptor will be closed by close().

mode = <attribute 'mode' of '_io.FileIO' objects>
  String giving the file mode

IncrementalNewlineDecoder

Codec used when reading a file in universal newlines mode.

It wraps another incremental decoder, translating \r\n and \r into \n.
It also records the types of newlines encountered.  When used with
translate=False, it ensures that the newline sequence is returned in
one piece. When used with decoder=None, it expects unicode strings as
decode input and translates newlines without first invoking an external
decoder.

decode(self, /, input, final=False)

getstate(self, /)

reset(self, /)

setstate(self, state, /)

newlines = <attribute 'newlines' of '_io.IncrementalNewlineDecoder' objects>

StringIO

Text I/O implementation using an in-memory buffer.

The initial_value argument sets the value of object.  The newline
argument is like the one of TextIOWrapper's constructor.

close(self, /)

  Close the IO object.

  Attempting any further operation after the object is closed
  will raise a ValueError.

  This method has no effect if the file is already closed.

detach(...)

  Separate the underlying buffer from the TextIOBase and return it.

  After the underlying buffer has been detached, the TextIO is in an
  unusable state.

fileno(self, /)

  Returns underlying file descriptor if one exists.

  OSError is raised if the IO object does not use a file descriptor.

flush(self, /)

  Flush write buffers, if applicable.

  This is not implemented for read-only and non-blocking streams.

getvalue(self, /)

  Retrieve the entire contents of the object.

isatty(self, /)

  Return whether this is an 'interactive' stream.

  Return False if it can't be determined.

read(self, size=-1, /)

  Read at most size characters, returned as a string.

  If the argument is negative or omitted, read until EOF
  is reached. Return an empty string at EOF.

readable(self, /)

  Returns True if the IO object can be read.

readline(self, size=-1, /)

  Read until newline or EOF.

  Returns an empty string if EOF is hit immediately.

readlines(self, hint=-1, /)

  Return a list of lines from the stream.

  hint can be specified to control the number of lines read: no more
  lines will be read if the total size (in bytes/characters) of all
  lines so far exceeds hint.

seek(self, pos, whence=0, /)

  Change stream position.

  Seek to character offset pos relative to position indicated by whence:
      0  Start of stream (the default).  pos should be >= 0;
      1  Current position - pos must be 0;
      2  End of stream - pos must be 0.
  Returns the new absolute position.

seekable(self, /)

  Returns True if the IO object can be seeked.

tell(self, /)

  Tell the current file position.

truncate(self, pos=None, /)

  Truncate size to pos.

  The pos argument defaults to the current file position, as
  returned by tell().  The current file position is unchanged.
  Returns the new absolute position.

writable(self, /)

  Returns True if the IO object can be written.

write(self, s, /)

  Write string to file.

  Returns the number of characters written, which is always equal to
  the length of the string.

writelines(self, lines, /)

  Write a list of lines to stream.

  Line separators are not added, so it is usual for each of the
  lines provided to have a line separator at the end.

closed = <attribute 'closed' of '_io.StringIO' objects>

encoding = <attribute 'encoding' of '_io._TextIOBase' objects>
  Encoding of the text stream.

  Subclasses should override.

errors = <attribute 'errors' of '_io._TextIOBase' objects>
  The error setting of the decoder or encoder.

  Subclasses should override.

line_buffering = <attribute 'line_buffering' of '_io.StringIO' objects>

newlines = <attribute 'newlines' of '_io.StringIO' objects>

TextIOWrapper

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.getpreferredencoding(False).

errors determines the strictness of encoding and decoding (see
help(codecs.Codec) or the documentation for codecs.register) and
defaults to "strict".

newline controls how line endings are handled. It can be None, '',
'\n', '\r', and '\r\n'.  It works as follows:


	On input, if newline is None, universal newlines mode is

  enabled. Lines in the input can end in '\n', '\r', or '\r\n', and
  these are translated into '\n' before being returned to the
  caller. If it is '', universal newline mode is enabled, but line
  endings are returned to the caller untranslated. If it has any of
  the other legal values, input lines are only terminated by the given
  string, and the line ending is returned to the caller untranslated.


	On output, if newline is None, any '\n' characters written are

  translated to the system default line separator, os.linesep. If
  newline is '' or '\n', no translation takes place. If newline is any
  of the other legal values, any '\n' characters written are translated
  to the given string.

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

close(self, /)

detach(self, /)

fileno(self, /)

flush(self, /)

isatty(self, /)

read(self, size=-1, /)

readable(self, /)

readline(self, size=-1, /)

readlines(self, hint=-1, /)

  Return a list of lines from the stream.

  hint can be specified to control the number of lines read: no more
  lines will be read if the total size (in bytes/characters) of all
  lines so far exceeds hint.

reconfigure(self, /, *, encoding=None, errors=None, newline=None, line_buffering=None, write_through=None)

  Reconfigure the text stream with new parameters.

  This also does an implicit stream flush.

seek(self, cookie, whence=0, /)

seekable(self, /)

tell(self, /)

truncate(self, pos=None, /)

writable(self, /)

write(self, text, /)

writelines(self, lines, /)

  Write a list of lines to stream.

  Line separators are not added, so it is usual for each of the
  lines provided to have a line separator at the end.

buffer = <member 'buffer' of '_io.TextIOWrapper' objects>

closed = <attribute 'closed' of '_io.TextIOWrapper' objects>

encoding = <member 'encoding' of '_io.TextIOWrapper' objects>

errors = <attribute 'errors' of '_io.TextIOWrapper' objects>

line_buffering = <member 'line_buffering' of '_io.TextIOWrapper' objects>

name = <attribute 'name' of '_io.TextIOWrapper' objects>

newlines = <attribute 'newlines' of '_io.TextIOWrapper' objects>

write_through = <member 'write_through' of '_io.TextIOWrapper' objects>

UnsupportedOperation

with_traceback(...)

  Exception.with_traceback(tb) --
      set self.__traceback__ to tb and return self.

args = <attribute 'args' of 'BaseException' objects>

characters_written = <attribute 'characters_written' of 'OSError' objects>

errno = <member 'errno' of 'OSError' objects>
  POSIX exception code

filename = <member 'filename' of 'OSError' objects>
  exception filename

filename2 = <member 'filename2' of 'OSError' objects>
  second exception filename

strerror = <member 'strerror' of 'OSError' objects>
  exception strerror

Functions

open

open(file, mode='r', buffering=-1, encoding=None, errors=None, newline=None, closefd=True, opener=None)

  Open file and return a stream.  Raise OSError upon failure.

  file is either a text or byte string giving the name (and the path
  if the file isn't in the current working directory) of the file to
  be opened or an integer file descriptor of the file to be
  wrapped. (If a file descriptor is given, it is closed when the
  returned I/O object is closed, unless closefd is set to False.)

  mode is an optional string that specifies the mode in which the file
  is opened. It defaults to 'r' which means open for reading in text
  mode.  Other common values are 'w' for writing (truncating the file if
  it already exists), 'x' for creating and writing to a new file, and
  'a' for appending (which on some Unix systems, means that all writes
  append to the end of the file regardless of the current seek position).
  In text mode, if encoding is not specified the encoding used is platform
  dependent: locale.getpreferredencoding(False) is called to get the
  current locale encoding. (For reading and writing raw bytes use binary
  mode and leave encoding unspecified.) The available modes are:

  ========= ===============================================================
  Character Meaning
  --------- ---------------------------------------------------------------
  'r'       open for reading (default)
  'w'       open for writing, truncating the file first
  'x'       create a new file and open it for writing
  'a'       open for writing, appending to the end of the file if it exists
  'b'       binary mode
  't'       text mode (default)
  '+'       open a disk file for updating (reading and writing)
  'U'       universal newline mode (deprecated)
  ========= ===============================================================

  The default mode is 'rt' (open for reading text). For binary random
  access, the mode 'w+b' opens and truncates the file to 0 bytes, while
  'r+b' opens the file without truncation. The 'x' mode implies 'w' and
  raises an `FileExistsError` if the file already exists.

  Python distinguishes between files opened in binary and text modes,
  even when the underlying operating system doesn't. Files opened in
  binary mode (appending 'b' to the mode argument) return contents as
  bytes objects without any decoding. In text mode (the default, or when
  't' is appended to the mode argument), the contents of the file are
  returned as strings, the bytes having been first decoded using a
  platform-dependent encoding or using the specified encoding if given.

  'U' mode is deprecated and will raise an exception in future versions
  of Python.  It has no effect in Python 3.  Use newline to control
  universal newlines mode.

  buffering is an optional integer used to set the buffering policy.
  Pass 0 to switch buffering off (only allowed in binary mode), 1 to select
  line buffering (only usable in text mode), and an integer > 1 to indicate
  the size of a fixed-size chunk buffer.  When no buffering argument is
  given, the default buffering policy works as follows:

  * Binary files are buffered in fixed-size chunks; the size of the buffer
    is chosen using a heuristic trying to determine the underlying device's
    "block size" and falling back on `io.DEFAULT_BUFFER_SIZE`.
    On many systems, the buffer will typically be 4096 or 8192 bytes long.

  * "Interactive" text files (files for which isatty() returns True)
    use line buffering.  Other text files use the policy described above
    for binary files.

  encoding is the name of the encoding used to decode or encode the
  file. This should only be used in text mode. The default encoding is
  platform dependent, but any encoding supported by Python can be
  passed.  See the codecs module for the list of supported encodings.

  errors is an optional string that specifies how encoding errors are to
  be handled---this argument should not be used in binary mode. Pass
  'strict' to raise a ValueError exception if there is an encoding error
  (the default of None has the same effect), or pass 'ignore' to ignore
  errors. (Note that ignoring encoding errors can lead to data loss.)
  See the documentation for codecs.register or run 'help(codecs.Codec)'
  for a list of the permitted encoding error strings.

  newline controls how universal newlines works (it only applies to text
  mode). It can be None, '', '\n', '\r', and '\r\n'.  It works as
  follows:

  * On input, if newline is None, universal newlines mode is
    enabled. Lines in the input can end in '\n', '\r', or '\r\n', and
    these are translated into '\n' before being returned to the
    caller. If it is '', universal newline mode is enabled, but line
    endings are returned to the caller untranslated. If it has any of
    the other legal values, input lines are only terminated by the given
    string, and the line ending is returned to the caller untranslated.

  * On output, if newline is None, any '\n' characters written are
    translated to the system default line separator, os.linesep. If
    newline is '' or '\n', no translation takes place. If newline is any
    of the other legal values, any '\n' characters written are translated
    to the given string.

  If closefd is False, the underlying file descriptor will be kept open
  when the file is closed. This does not work when a file name is given
  and must be True in that case.

  A custom opener can be used by passing a callable as *opener*. The
  underlying file descriptor for the file object is then obtained by
  calling *opener* with (*file*, *flags*). *opener* must return an open
  file descriptor (passing os.open as *opener* results in functionality
  similar to passing None).

  open() returns a file object whose type depends on the mode, and
  through which the standard file operations such as reading and writing
  are performed. When open() is used to open a file in a text mode ('w',
  'r', 'wt', 'rt', etc.), it returns a TextIOWrapper. When used to open
  a file in a binary mode, the returned class varies: in read binary
  mode, it returns a BufferedReader; in write binary and append binary
  modes, it returns a BufferedWriter, and in read/write mode, it returns
  a BufferedRandom.

  It is also possible to use a string or bytearray as a file for both
  reading and writing. For strings StringIO can be used like a file
  opened in a text mode, and for bytes a BytesIO can be used like a file
  opened in a binary mode.

open_code

open_code(path)

  Opens the provided file with the intent to import the contents.

  This may perform extra validation beyond open(), but is otherwise interchangeable
  with calling open(path, 'rb').

text_encoding

text_encoding(encoding, stacklevel=2, /)

  A helper function to choose the text encoding.

  When encoding is not None, just return it.
  Otherwise, return the default text encoding (i.e. "locale").

  This function emits an EncodingWarning if encoding is None and
  sys.flags.warn_default_encoding is true.

  This can be used in APIs with an encoding=None parameter.
  However, please consider using encoding="utf-8" for new APIs.

Other members

DEFAULT_BUFFER_SIZE = 8192