AttributeError: 'NoneType' object has no attribute 'get_type_string'

[arjanz]

Discussed in #376

^{Originally posted by klemendrobnic February 6, 2024}
I would need help with resolving an error that occurs when im trying to use compose_call function.

from substrateinterface import SubstrateInterface

substrate = SubstrateInterface(url="wss://ws.framenode-7.s4.stg1.sora2.soramitsu.co.jp")


call = substrate.compose_call(call_module='Balances',call_function='transfer',call_params={'dest': '5CvxUr1gXDvAN8qEDPBFVdnF7QcPwNfYCQLYDDr3cCzC45Vt','value': 1 * 10**12})

I get the following error:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/klemendrobnic/.local/lib/python3.10/site-packages/substrateinterface/base.py", line 1408, in compose_call
    call.encode({
  File "/home/klemendrobnic/.local/lib/python3.10/site-packages/scalecodec/base.py", line 929, in encode
    self.data = self.process_encode(self.value_serialized)
  File "/home/klemendrobnic/.local/lib/python3.10/site-packages/scalecodec/types.py", line 1652, in process_encode
    call_type_string = self.call_module['calls'].value_object.get_type_string()
AttributeError: 'NoneType' object has no attribute 'get_type_string'

When i print the call_module that is called in the process_encode method i get the object printed, however the parameter calls is not included (call_type_string = self.call_module['calls'].value_object.get_type_string()) -> the code fails here
Thanks for any suggestions

After examining the metadata of the runtime, I found out that the Balances pallet for the endpoint you provided has in fact no runtime calls at all (so call transfer couldn't be found). You can also check PolkadotJS

However, the error handler could be improved here, the current thrown exception is indeed confusing and should be something like Call function 'transfer' not found. I'll make an issue for this.

[arjanz]

Fix released in https://github.com/polkascan/py-scale-codec/releases/tag/v1.2.8