Lines are defined slightly differently depending on whether the stream is a binary stream yielding bytes , or a text stream yielding character strings. See readline below. IOBase is also a context manager and therefore supports the with statement. IOBase provides these data attributes and methods:.
Flush and close this stream. This method has no effect if the file is already closed. Once the file is closed, any operation on the file e. As a convenience, it is allowed to call this method more than once; only the first call, however, will have an effect. True if the stream is closed. Return the underlying file descriptor an integer of the stream if it exists.
Flush the write buffers of the stream if applicable. This does nothing for read-only and non-blocking streams. Return True if the stream is interactive i. Return True if the stream can be read from.
If False , read will raise OSError. Read and return one line from the stream. If size is specified, at most size bytes will be read. Read and return a list of lines from the stream. Change the stream position to the given byte offset. Values for whence are:. The valid values for a file could depend on it being open in text or binary mode. Return True if the stream supports random access. If False , seek , tell and truncate will raise OSError. Resize the stream to the given size in bytes or the current position if size is not specified.
This resizing can extend or reduce the current file size. In case of extension, the contents of the new file area depend on the platform on most systems, additional bytes are zero-filled. The new file size is returned. Return True if the stream supports writing. If False , write and truncate will raise OSError. Write a list of lines to the stream.
Line separators are not added, so it is usual for each of the lines provided to have a line separator at the end. Prepare for object destruction. Base class for raw binary streams. It inherits IOBase. Raw binary streams typically provide low-level access to an underlying OS device or API, and do not try to encapsulate it in high-level primitives this functionality is done at a higher-level in buffered binary streams and text streams, described later in this page.
Read up to size bytes from the object and return them. As a convenience, if size is unspecified or -1, all bytes until EOF are returned. Otherwise, only one system call is ever made. Fewer than size bytes may be returned if the operating system call returns fewer than size bytes.
If 0 bytes are returned, and size was not 0, this indicates end of file. If the object is in non-blocking mode and no bytes are available, None is returned. The default implementation defers to readall and readinto. Read and return all the bytes from the stream until EOF, using multiple calls to the stream if necessary.
Read bytes into a pre-allocated, writable bytes-like object b , and return the number of bytes read. For example, b might be a bytearray. Write the given bytes-like object , b , to the underlying raw stream, and return the number of bytes written. This can be less than the length of b in bytes, depending on specifics of the underlying raw stream, and especially if it is in non-blocking mode.
None is returned if the raw stream is set not to block and no single byte could be readily written to it. The caller may release or mutate b after this method returns, so the implementation should only access b during the method call.
Base class for binary streams that support some kind of buffering. The main difference with RawIOBase is that methods read , readinto and write will try respectively to read as much input as requested or to consume all given output, at the expense of making perhaps more than one system call.
In addition, those methods can raise BlockingIOError if the underlying raw stream is in non-blocking mode and cannot take or give enough data; unlike their RawIOBase counterparts, they will never return None. Besides, the read method does not have a default implementation that defers to readinto. Some buffers, like BytesIO , do not have the concept of a single raw stream to return from this method. They raise UnsupportedOperation. Read and return up to size bytes.
If the argument is omitted, None , or negative, data is read and returned until EOF is reached. An empty bytes object is returned if the stream is already at 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.
The io. It wraps the OS-level file descriptor in an object which we can use to access the file in a Pythonic way. The os. It does not return a file object; the returned value will not have read or write functions. Overall, io. In this lesson, we studied simple operations of python IO module and how we can manage the Unicode characters with BytesIO as well. I haven't tried any of this myself, but check out this answer — Allie Fitter. A Python 2 relic, so it should use str instead.
I haven't run this code in three years, so I'm not sure what else in it isn't compatible with Python 3. Show 1 more comment. Rajat Soni Rajat Soni 5 5 silver badges 9 9 bronze badges. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast Who is building clouds for the independent developer?
Exploding turkeys and how not to thaw your frozen bird: Top turkey questions Featured on Meta. Now live: A fully responsive profile. Project: incubator-spot Author: apache File: serializer. BinaryDecoder io. DatumReader avro. DatumWriter avro. BytesIO try: writer. BinaryEncoder rawbytes return rawbytes except avro. AvroTypeException: logging. Project: AboveTustin Author: kevinabrandon File: screenshot.
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