Python API Reference¶
getcurrent() → greenlet¶
Returns the current greenlet (i.e. the one which called this function).
greenlet(run=None, parent=None) → greenlet¶
Creates a new greenlet object (without running it).
run – The callable to invoke.
parent – The parent greenlet. The default is the current greenlet.
Greenlets support boolean tests:
bool(g)is true if
gis active and false if it is dead or not yet started.
Switches execution to this greenlet. See Switching Between Greenlets: Passing Objects and Control.
Switches execution to this greenlet, but immediately raises the given exception in this greenlet. If no argument is provided, the exception defaults to
greenlet.GreenletExit. The normal exception propagation rules apply, as described for
switch. Note that calling this method is almost equivalent to the following:
def raiser(): raise typ, val, tb g_raiser = greenlet(raiser, parent=g) g_raiser.switch()
except that this trick does not work for the
greenlet.GreenletExitexception, which would not propagate from
True if this greenlet is dead (i.e., it finished its execution).
gwill run. Writable; defaults to
None, reflecting that a greenlet starts execution in an empty context unless told otherwise. Generally, this should only be set once, before a greenlet begins running. Accessing or modifying this attribute raises
AttributeErroron Python versions 3.6 and earlier (which don’t natively support the
contextvarsmodule) or if
greenletwas built without contextvars support.
For more information, see Context Variables (asyncio).
New in version 1.0.0.
The frame that was active in this greenlet when it most recently called
some_other_greenlet.switch(), and that will resume execution when
this_greenlet.switch()is next called. The remainder of the greenlet’s stack can be accessed by following the frame object’s
gr_frameis non-None only for suspended greenlets; it is None if the greenlet is dead, not yet started, or currently executing.
The parent greenlet. This is writable, but it is not allowed to create cycles of parents.
A greenlet without a parent is the main greenlet of its thread.
Cannot be set to anything except a greenlet.
The callable that this greenlet will run when it starts. After it is started, this attribute no longer exists.
Subclasses can define this as a method on the type.
For details on tracing, see Tracing And Profiling.