RxPY - Connectable Operators



publish

This method will convert the observable into a connectable observable.

Syntax

publish(mapper=None)

Parameters

mapper: optional. A function used to multicast source values multiple times, without having to do multiple subscriptions.

Example

from rx import create, range, operators as op
import random
def test_observable(observer, scheduler):
   observer.on_next(random.random())
   observer.on_completed()
source = create(test_observable).pipe(op.publish())
test1 = source.subscribe(on_next = lambda i: print("From subscriber 1 - {0}".format(i)))
test2 = source.subscribe(on_next = lambda i: print("From subscriber 2 –
{0}".format(i)))
source.connect()

Output

E:\pyrx>python testrx.py
From subscriber 1 - 0.14751607273318490
From subscriber 2 - 0.1475160727331849

ref_count

This operator will make the observable a normal observable.

Syntax

ref_count()

Example

from rx import create, operators as op
import random
def test_observable(observer, scheduler):
   observer.on_next(random.random())
source = create(test_observable).pipe(op.publish(),op.ref_count())
test1 = source.subscribe(on_next = lambda i: print("From subscriber 1 - {0}".format(i)))
test2 = source.subscribe(on_next = lambda i: print("From subscriber 2 - {0}".format(i)))

Output

E:\pyrx>python testrx.py
From subscriber 1 - 0.8230640432381131

replay

This method works similar to the replaySubject. This method will return the same values, even if the observable has already emitted, and some of the subscribers are late in subscribing.

Syntax

replay()

Example

from rx import create, range, operators as op
import random
from threading import Timer
def test_observable(observer, scheduler):
   observer.on_next(random.random())
   observer.on_completed()
source = create(test_observable).pipe(op.replay())
test1 = source.subscribe(on_next = lambda i: print("From subscriber 1 - {0}".format(i)))
test2 = source.subscribe(on_next = lambda i: print("From subscriber 2 - {0}".format(i)))
source.connect()
print("subscriber called after delay ")
def last_subscriber():
   test3 = source.subscribe(on_next = lambda i: print("From subscriber 3 - {0}".format(i)))
t = Timer(5.0, last_subscriber)
t.start()

Output

E:\pyrx>python testrx.py
From subscriber 1 - 0.8340998157725388
From subscriber 2 - 0.8340998157725388
subscriber called after delay
From subscriber 3 - 0.8340998157725388
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