select – wait for events on a set of streams

This module provides functions to wait for events on streams (select streams which are ready for operations).

Pyboard specifics

Polling is an efficient way of waiting for read/write activity on multiple objects. Current objects that support polling are: pyb.UART, pyb.USB_VCP.



Create an instance of the Poll class., wlist, xlist[, timeout])

Wait for activity on a set of objects.

This function is provided for compatibility and is not efficient. Usage of Poll is recommended instead.

class Poll


poll.register(obj[, eventmask])

Register obj for polling. eventmask is 1 for read, 2 for write, 3 for read-write.


Unregister obj from polling.

poll.modify(obj, eventmask)

Modify the eventmask for obj.


Wait for at least one of the registered objects to become ready. Returns list of ready objects, or empty list on timeout.

Timeout is in milliseconds.