web3.py ( web3.exceptions.CannotHandleRequest: Could not discover provider while making request: method:eth_call ) --help

Question

proveedores= ['https://mainnet.infura.io/v3/KEY_KEY','https://ropsten.infura.io/v3/KEY_KEY']

from web3 import Web3 , HTTPProvider, IPCProvider, WebsocketProvider
from web3.auto import w3

web3= Web3(Web3.HTTPProvider(proveedores[0], request_kwargs={'timeout': 60}))


textABI= '[{"inputs":[{"intern...'

abij= json.loads(textABI)
dress= {'aDAI': {'address': '0xfC1E690f61EFd961294b3e1Ce3313fBD8aa4f85d', 'decimals': 18}}


contract1 = w3.eth.contract(address= "0xfC1E690f61EFd961294b3e1Ce3313fBD8aa4f85d", abi=abij)


# THIS FUNCTIONS ERRORS
buildContract= contract1.functions.name().call()
print(buildContract)

# THIS FUNCTION ERRORS
buildContract= contract1.functions.symbol().call()
print(buildContract)

Functions of this contract:

dict_keys(['abi', 'web3', 'address', '_functions', 'UINT_MAX_VALUE', 'allowInterestRedirectionTo', 'allowance', 'approve', 'balanceOf', 'burnOnLiquidation', 'decimals', 'decreaseAllowance', 'getInterestRedirectionAddress', 'getRedirectedBalance', 'getUserIndex', 'increaseAllowance', 'isTransferAllowed', 'mintOnDeposit', 'name', 'principalBalanceOf', 'redeem', 'redirectInterestStream', 'redirectInterestStreamOf', 'symbol', 'totalSupply', 'transfer', 'transferFrom', 'transferOnLiquidation', 'underlyingAssetAddress'])

Error from contract1:

Traceback (most recent call last):
  File "PATH/proyect7.py", line 82, in <module>
    buildContract= contract1.functions.symbol().call()
  File "PATH\env\lib\site-packages\web3\contract.py", line 964, in call
    **self.kwargs
  File "PATH\env\lib\site-packages\web3\contract.py", line 1499, in call_contract_function
    return_data = web3.eth.call(call_transaction, block_identifier=block_id)
  File "PATH\env\lib\site-packages\eth_utils\functional.py", line 45, in inner
    return callback(fn(*args, **kwargs))
  File "PATH\env\lib\site-packages\web3\eth.py", line 434, in call
    [transaction, block_identifier],
  File "PATH\env\lib\site-packages\web3\manager.py", line 149, in request_blocking
    response = self._make_request(method, params)
  File "PATH\env\lib\site-packages\web3\manager.py", line 128, in _make_request
    return request_func(method, params)
  File "cytoolz/functoolz.pyx", line 250, in cytoolz.functoolz.curry.__call__
    return self.func(*args, **kwargs)
  File "PATH\env\lib\site-packages\web3\middleware\formatting.py", line 76, in apply_formatters
    response = make_request(method, params)
  File "PATH\env\lib\site-packages\web3\middleware\gas_price_strategy.py", line 34, in middleware
    return make_request(method, params)
  File "cytoolz/functoolz.pyx", line 250, in cytoolz.functoolz.curry.__call__
    return self.func(*args, **kwargs)
  File "PATH\env\lib\site-packages\web3\middleware\formatting.py", line 74, in apply_formatters
    response = make_request(method, formatted_params)
  File "PATH\env\lib\site-packages\web3\middleware\attrdict.py", line 33, in middleware
    response = make_request(method, params)
  File "cytoolz/functoolz.pyx", line 250, in cytoolz.functoolz.curry.__call__
    return self.func(*args, **kwargs)
  File "PATH\env\lib\site-packages\web3\middleware\formatting.py", line 74, in apply_formatters
    response = make_request(method, formatted_params)
  File "PATH\env\lib\site-packages\web3\middleware\normalize_errors.py", line 25, in middleware
    result = make_request(method, params)
  File "cytoolz/functoolz.pyx", line 250, in cytoolz.functoolz.curry.__call__
    return self.func(*args, **kwargs)
  File "PATH\env\lib\site-packages\web3\middleware\formatting.py", line 74, in apply_formatters
    response = make_request(method, formatted_params)
  File "cytoolz/functoolz.pyx", line 250, in cytoolz.functoolz.curry.__call__
    return self.func(*args, **kwargs)
  File "PATH\env\lib\site-packages\web3\middleware\formatting.py", line 74, in apply_formatters
    response = make_request(method, formatted_params)
  File "PATH\env\lib\site-packages\web3\providers\auto.py", line 94, in make_request
    return self._proxy_request(method, params)
  File "PATH\env\lib\site-packages\web3\providers\auto.py", line 111, in _proxy_request
    params))
web3.exceptions.CannotHandleRequest: Could not discover provider while making request: method:eth_call
params:[{'to': '0xfC1E690f61EFd961294b3e1Ce3313fBD8aa4f85d', 'data': '0x95d89b41'}, 'latest']

Can someone explaine the error that I get when using these parameters with web3.py?

Answer 1

I had bad imports:

from web3 import Web3, HTTPProvider, IPCProvider, WebsocketProvider
from web3.auto import w3

Fixed imports:

from web3 import Web3

Answer 2

I had the same problem. Has anyone figured out what is causing this. I have used the imports suggested above but still get the error:

from web3 import Web3

Answer 3

I had a similar problem, the issue is your Web3 object does not recognize the provider. It gets resloved with this:

from web3 import Web3


my_provider = Web3.HTTPProvider(<http rpc (infura | alchemy)>)
w3 = Web3(my_provider)

nonce = w3.eth.get_transaction_count(public_key)

Basically any method that needs to read data off of the blockchain will require a provider.