Utility Functions

Utilities defines several 'helper' functions to create contracts and accounts.

Utility Functions
- Functions

Functions

generate_random address

Create a random Ethereum address

def generate_random_address() -> str

Returns: an address

Example:

address = generate_random_address()

create_account

Create an account in the EVM

def create_account(
                  evm: PyEvmLocal | PyEvmFork,
                  address: str = None
                  value: int = 0) -> str

Parameters:

evm: PyEvmLocal | PyEvmForm. the EVM client
address: str optional. if set it will be used for the account address. Otherwise a random address will be generated.
value : int optional. create an initial balance for the account in ether

Returns: the address

Example:

evm = PyEvmLocal()
bob = create_address(evm)

create_many_accounts

Create many accounts in the EVM. Address are randomly generated

def create_many_account(
                  evm: PyEvmLocal | PyEvmFork,
                  num: int
                  value: int
                  value: int = 0) -> typing.List[str]

Parameters

evm: PyEvmLocal | PyEvmForm. the EVM client
num: int. the number of accounts to create.
value : int optional. create an initial balance for each account in ether

Returns a list of addresses

Example:

evm = PyEvmLocal()
# create 2 accounts, each with a balance of 1 Ether
[bob, alice] = create_many_address(evm, 2, 1)

contract_from_raw_abi

Create the contract given the full ABI. Full ABI should include abi and bytecode. This is usually a single json file from a compiled Solidity contract.

def contract_from_raw_abi(
                          evm: evm: PyEvmLocal | PyEvmFork
                          raw_abi: str) -> Contract

Parameters

evm : PyEvmLocal | PyEvmForm. the EVM client
raw_abi : abi file as un-parsed json

Returns an instance of Contract

Example:

evm = PyEvmLocal()
with open('counter.json') as f:
    raw = f.read()

contract = contract_from_raw_abi(evm, raw)

contract_from_abi_bytecode

Create a contract given the abi and bytecode.

def contract_from_abi_bytecode(
                               evm: evm: PyEvmLocal | PyEvmFork
                               raw_abi: str, 
                               bytecode: bytes) -> Contract
)

Parameters

evm : PyEvmLocal | PyEvmForm. the EVM client
raw_abi : abi file as un-parsed json
bytecode: bytes

Returns an instance of Contract

Example:

evm = PyEvmLocal()
with open('counter.abi') as f:
    abi = f.read()

with open('counter.bin') as f:
    bytecode = f.read()

bits = bytes.fromhex(bytecode)
contract = contract_from_abi_bytecode(abi, bits)

contract_from_inline_abi

Create the contract using inline ABI method definitions.

def contract_from_inline_abi(
                             evm: evm: PyEvmLocal | PyEvmFork)
                             abi: typing.List[str]) -> Contract

Function are described in the format: function NAME(PARAMETER TYPES) (RETURN TYPES)

where:

NAME if the function name
PARAMETER TYPES are 0 or more solidity types of any arguments to the function
RETURN TYPES are any expected returned solidity types. If the function does not return anything, this is not needed.

Examples:

"function hello(uint256,uint256)" is hello function the expects 2 int arguments and returns nothing
"function hello()(uint256)" is a hello function with no arguments and return an int

Parameters

evm : PyEvmLocal | PyEvmForm. the EVM client
abi : a list of strs

Returns an instance of Contract

Example:

evm = PyEvmLocal()
abi = ['function hello()(uint256)', 'function world(string) (string)']
contract = contract_from_inline_abi(evm, abi)

Simular Documentation