• Web3.py version 4.2.1
  • geth version: 1.8.0-unstable

I have followed web3.py guide for filtering.

Through the contract instance api:

event_filter = mycontract.events.myEvent.createFilter(fromBlock='latest', {'filter':{'arg1':10}})

But I get an error for this line:

myContract.events.LogJob.createFilter(fromBlock='latest', {'filter': {'arg1':10}})

My main goal is the filter events based on their arguments.

Error I am having:

myContract.events.LogJob.createFilter(fromBlock='latest', {'filter': {'arg1':10}})
SyntaxError: positional argument follows keyword argument

[Q] How could I fix this error?

Update: I have followed @Mikko Ohtamaa 's answer. Now I do not get any error, but filter returns [] even I provide correct event's keyword (dictionary of argument name and its value).

Please see an example:

blockReadFrom = 1899201;
myFilter = eBlocBroker.events.LogJob.createFilter(fromBlock=blockReadFrom)

Returns, here you can see that there is emitted event with 'storageID': 0 under AttributeDict:

[AttributeDict({'address': '0x128c9F368F12C24Cc2a4f88dCDCf3daA13C9667e', 'transactionHash': HexBytes('0x8f7c50fe276057ea90985be6d14dc7abb79ee0430c66bd161861b582b7db0c97'), 'args': AttributeDict({'desc': 'Science', 'jobKey': 'QmRsaBEGcqxQcJbBxCi1LN9iz5bDAGDWR6Hx7ZvWqgqmdR', 'index': 21, 'storageID': 0, 'clusterAddress': '0x75A4c787c5c18C587B284a904165Ff06a269B48C'}), 'transactionIndex': 0, 'event': 'LogJob', 'blockHash': HexBytes('0x9782cb281aa72defe54e0f84055a03a0b1bf6c6f21bd3d276a1252098f83c15f'), 'logIndex': 0, 'blockNumber': 1899201})]

blockReadFrom = 1899201;
myFilter = eBlocBroker.events.LogJob.createFilter(fromBlock=blockReadFrom, argument_filters={'storageID':0})



And interesting point that following line returns a valid output even though {'arg1': 999 or 'arg111': 999 etc.} does not exists.

myFilter = eBlocBroker.events.LogJob.createFilter(fromBlock=blockReadFrom, argument_filters={'arg1': 999})


For more information please follow this closed issue: https://github.com/ethereum/web3.py/issues/943#event-1723643072

1 Answer 1


I think it should be:

  myContract.events.LogJob.createFilter(fromBlock='latest', argument_filters={'arg1':10})

You can see the actual function signature here:


Please file an issue regarding web3.py documentation page as it does not reflect the current codebase.

  • Should arg1 be the keyword that is defined under the event ? Now it does not give any error, but it returns [] even I provide correct event's keyword (dictionary of argument name and its value). Please see my updated answer @Mikko Ohtamaa
    – alper
    Commented Jul 3, 2018 at 9:30
  • For more information please follow this closed issue: github.com/ethereum/web3.py/issues/943#event-1723643072
    – alper
    Commented Jul 18, 2018 at 15:56

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