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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.
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
Base class for buffered IO objects. The main difference with RawIOBase is that the read() method supports omitting the size argument, and does not have a default implementation that defers to readinto(). In addition, read(), readinto() and write() may raise BlockingIOError if the underlying raw stream is in non-blocking mode and not ready; unlike their raw counterparts, they will never return None. A typical implementation should not inherit from a RawIOBase implementation, but wrap one.
close(self, /) Flush and close the IO object. This method has no effect if the file is already closed.
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, /) Flush write buffers, if applicable. This is not implemented for read-only and non-blocking streams.
isatty(self, /) Return whether this is an 'interactive' stream. Return False if it can't be determined.
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(...) 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(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._IOBase' objects>
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>
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>
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>
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>
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.
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*).
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
The abstract base class for all I/O classes.
This class provides dummy implementations for many methods that
derived classes can override selectively; the default implementations
represent a file that cannot be read, written or seeked.
Even though IOBase does not declare read, readinto, or write because
their signatures will vary, implementations and clients should
consider those methods part of the interface. Also, implementations
may raise UnsupportedOperation when operations they do not support are
called.
The basic type used for binary data read from or written to a file is
bytes. Other bytes-like objects are accepted as method arguments too.
In some cases (such as readinto), a writable object is required. Text
I/O classes work with str data.
Note that calling any method (except additional calls to close(),
which are ignored) on a closed stream should raise a ValueError.
IOBase (and its subclasses) support the iterator protocol, meaning
that an IOBase object can be iterated over yielding the lines in a
stream.
IOBase also supports the :keyword:`with` statement. In this example,
fp is closed after the suite of the with statement is complete:
with open('spam.txt', 'r') as fp:
fp.write('Spam and eggs!')
close(self, /) Flush and close the IO object. This method has no effect if the file is already closed.
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.
isatty(self, /) Return whether this is an 'interactive' stream. Return False if it can't be determined.
readable(self, /) Return whether object was opened for reading. If False, read() will raise OSError.
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(self, /) Return whether object was opened for writing. If False, write() will raise OSError.
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._IOBase' objects>
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>
Base class for raw binary I/O.
close(self, /) Flush and close the IO object. This method has no effect if the file is already closed.
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.
isatty(self, /) Return whether this is an 'interactive' stream. Return False if it can't be determined.
read(self, size=-1, /)
readable(self, /) Return whether object was opened for reading. If False, read() will raise OSError.
readall(self, /) Read until EOF, using multiple read() call.
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(...) 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(self, /) Return whether object was opened for writing. If False, write() will raise OSError.
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._IOBase' objects>
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>
Base class for text I/O. This class provides a character and line based interface to stream I/O. There is no readinto method because Python's character strings are immutable.
close(self, /) Flush and close the IO object. 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.
isatty(self, /) Return whether this is an 'interactive' stream. Return False if it can't be determined.
read(...) Read at most n characters from stream. Read from underlying buffer until we have n characters or we hit EOF. If n is negative or omitted, read until EOF.
readable(self, /) Return whether object was opened for reading. If False, read() will raise OSError.
readline(...) 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(...) 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(self, /) Return whether object was opened for writing. If False, write() will raise OSError.
write(...) Write string to stream. 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._IOBase' 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.
newlines = <attribute 'newlines' of '_io._TextIOBase' objects> Line endings translated so far. Only line endings translated during reading are considered. Subclasses should override.
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:
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>
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
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(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(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.
DEFAULT_BUFFER_SIZE = 8192
SEEK_CUR = 1
SEEK_END = 2
SEEK_SET = 0