asyncio.WriteTransport

class asyncio.WriteTransport

Interface for write-only transports.

abort()

Close the transport immediately, without waiting for pending operations to complete. Buffered data will be lost. No more data will be received. The protocol’s connection_lost() method will eventually be called with None as its argument.

can_write_eof()

Return True if the transport supports write_eof(), False if not.

get_write_buffer_size()

Return the current size of the output buffer used by the transport.

get_write_buffer_limits()

Get the high- and low-water limits for write flow control. Return a tuple (low, high) where low and high are positive number of bytes.

Use set_write_buffer_limits() to set the limits.

New in version 3.4.2.

set_write_buffer_limits(high=None, low=None)

Set the high- and low-water limits for write flow control.

These two values control when call the protocol’s pause_writing() and resume_writing() methods are called. If specified, the low-water limit must be less than or equal to the high-water limit. Neither high nor low can be negative.

The defaults are implementation-specific. If only the high-water limit is given, the low-water limit defaults to an implementation-specific value less than or equal to the high-water limit. Setting high to zero forces low to zero as well, and causes pause_writing() to be called whenever the buffer becomes non-empty. Setting low to zero causes resume_writing() to be called only once the buffer is empty. Use of zero for either limit is generally sub-optimal as it reduces opportunities for doing I/O and computation concurrently.

Use get_write_buffer_limits() to get the limits.

write(data)

Write some data bytes to the transport.

This method does not block; it buffers the data and arranges for it to be sent out asynchronously.

writelines(list_of_data)

Write a list (or any iterable) of data bytes to the transport. This is functionally equivalent to calling write() on each element yielded by the iterable, but may be implemented more efficiently.

write_eof()

Close the write end of the transport after flushing buffered data. Data may still be received.

This method can raise NotImplementedError if the transport (e.g. SSL) doesn’t support half-closes.