Web3.py: How to print received messages right away using watch(callback) or request get_new_entries() on shh_filter?

[avatar-lavventura]

• Web3.py version: 4.2.1
• Python: 3.5.2
• OS: linux
• geth version: 1.8.0-unstable
• I am running geth with --shh flag and --rpcapi "admin,eth,net,web3,debug,shh"

---

I have followed docs. My simple goal is the print received messages via using watch().

Returns ShhFilter which you can either watch(callback) or request get_new_entries()
$ web3.shh.newMessageFilter({'topic': '0x12340000', 'privateKeyID': recipient_private})
ShhFilter({'filter_id': 'b37c3106cfb683e8f01b5019342399e0d1d74e9160f69b27625faba7a6738554'})

=> Could you please provide a simple example to watch() or request get_new_entries() for the ShhFilter? I just want new received messages to printed on the screen.

I was able to create a filter but it does not print the received messages right away, I need to manually call it such as: print(received_messages[0]).

Example approach on web3.js is:

> web3.shh.newMessageFilter(
        {privateKeyID:kId}, 
        function(err, res) {console.log(web3.toUtf8(res.payload))});

---

This is how far I get:

from web3 import Web3, HTTPProvider
web3 = Web3(HTTPProvider('http://localhost:8545'))
from web3.shh import Shh
Shh.attach(web3, "shh")

print(web3.shh.info)
pKey = '0xa82ff6abcf75393084edb06d100e53268c5e118884d59282ef9d3396c8537011'; #web3.shh.newKeyPair();
kId = web3.shh.addPrivateKey(pKey)

print(web3.shh.hasKeyPair(kId))
print('PubKey: ' + web3.shh.getPublicKey(kId))

myFilter = web3.shh.newMessageFilter({'topic': '0x07678231', 'privateKeyID': kId})

myFilter.poll_interval = 500;
print(myFilter.poll_interval) 
print(myFilter.filter_id) # Here I obtain the filter-id

received_messages = [];
myFilter.watch(received_messages.extend)  # This stores the coming messages in received_messages but it does not print on screen when new message is received.# <TimerClass(Thread-4, started daemon 139988713903872)>

Thank you for your valuable help and guide.

[dylanjw]

Replace received_messages.extend with a callback function that does everthing you want with new messages. ie:

received_messages = []
def print_message(received_message):
    print(received_message)
    received_messages.append(received_message)

myFilter.watch(print_message)

[avatar-lavventura]

My simple example filter:

   myFilter = eBlocBroker.events.LogJob.createFilter(
       fromBlock=857060,
       argument_filters={'clusterAddress': '0x4e4a0750350796164D8DefC442a712B7557BF282'}
   )
   received_messages = []
   myFilter.watch(print_message)

---

=> I am having following error: AttributeError: #'LogFilter' object has no attribute 'watch'.

I guess Watch callback return value exists on Web3.js but it does no exist on Web3.py. @dylanjw

[dylanjw]

We removed the watch method from the log objects. For some reason it is still lingering in the Shh filter. Have a look at doc for the rationale and some examples for implementing your own asynchronous polling: http://web3py.readthedocs.io/en/latest/filters.html#examples-listening-for-events