How to dump/access contract storage in Brownie console?

Question

In Brownie console, for a deployed contract, public contract attributes can be accessed with contract.nameOfAttribute(). This does not work for private attributes - how can one access private attribute values from the Brownie console? More generally, how does one dump the ongoing contract's state/storage from the Brownie console?

Answer 1

• Here is the original code using web3.py
• I have updated this version for brownie

#!/usr/bin/python3
from brownie import web3
from hexbytes import HexBytes


def display_storage(address, height=100, width=100):
    for i in range(100):
        # Regular slots
        rs = web3.eth.get_storage_at(address, i)
        if rs != HexBytes(
            "0x0000000000000000000000000000000000000000000000000000000000000000"
        ):
            print(i, rs)

        # Slots for large values
        slot = web3.solidityKeccak(["uint256"], [i])
        slot_int = int(slot.hex(), 16)
        for j in range(100):
            s = web3.eth.get_storage_at(address, slot_int + j)
            if s != HexBytes(
                "0x0000000000000000000000000000000000000000000000000000000000000000"
            ):
                print(slot_int + j, s)


display_storage("0x876807312079af775c49c916856A2D65f904e612")

If you get an error like this

ValueError: {'code': -32602, 'message': 'Errors encountered in param 1: Storage slot argument must have a length of 66 ("0x" + 32 bytes), but \'0x0\' has a length of 3', 'data': {'message': 'Errors encountered in param 1: Storage slot argument must have a length of 66 ("0x" + 32 bytes), but \'0x0\' has a length of 3'}}

• You can fix this by modifying the value of i from int to 32 bytes hex str. Updated script.

#!/usr/bin/python3
from brownie import web3
from hexbytes import HexBytes


def display_storage(address, height=100, width=100):
    for i in range(100):
        # Regular slots
        rs = web3.eth.get_storage_at(address, i.to_bytes(32, byteorder="big")).hex()
        if rs != "0x0000000000000000000000000000000000000000000000000000000000000000":
            print(i, rs)

        # Slots for large values
        slot = i.to_bytes(32, byteorder="big")
        slot_int = int.from_bytes(slot, byteorder="big")
        for j in range(100):
            s = web3.eth.get_storage_at(
                address, "0x" + hex(slot_int + j)[2:].zfill(64)
            ).hex()
            # print(s)
            if (
                s
                != "0x0000000000000000000000000000000000000000000000000000000000000000"
            ):
                print(i, s)


if __name__ == "__main__":
    display_storage("0x876807312079af775c49c916856A2D65f904e612")

• Notice the value of i now changed to i.to_bytes(32, byteorder="big")