eth-typing: Common type annotations for ethereum python packages

6.0.0 · active · verified Thu Apr 09

eth-typing provides common type annotations for various Ethereum Python packages, offering a standardized set of types for improved type hinting and code clarity across the Ethereum ecosystem. It is actively maintained with frequent releases, currently at version 6.0.0, supporting modern Python versions. [1, 2, 5]

Warnings

breaking Version 6.0.0 drops support for Python 3.8 and 3.9. Users on these Python versions should remain on `eth-typing<6` or upgrade their Python environment. [10]
Fix: Upgrade Python to 3.10+ or pin `eth-typing` version to `<6.0.0`.
deprecated Several ABI-related TypedDict attributes (e.g., `constant`, `payable` in function types) are deprecated in favor of `stateMutability`. Additionally, specific function types (`ABIFunction`, `ABIConstructor`, etc.) should be used instead of the general `ABIElement` for clarity. [1, 9]
Fix: Review ABI definitions and update them to use `stateMutability` and more specific ABI element types as recommended by the documentation.
gotcha Many fields in `eth-typing`'s `TypedDict` definitions (especially in `eth_typing.abi`) use `typing.NotRequired`. This means type checkers will not enforce their presence. Developers expecting all fields to be mandatory might face unexpected `KeyError`s at runtime if not handled defensively. [1]
Fix: Be aware of `NotRequired` fields in `TypedDicts`. Explicitly check for key existence or provide default values when accessing such fields. Type checkers will warn if you access a `NotRequired` field without a check if `strict` mode is enabled.

Install

pip install eth-typing Install stable version

Imports

TypeStr
```
from eth_typing import TypeStr
```
HexStr
```
from eth_typing.encoding import HexStr
```
Address
```
from eth_typing.evm import Address
```
Specific EVM-related types are found in submodules like `eth_typing.evm`.
ChecksumAddress
```
from eth_typing.evm import ChecksumAddress
```
Use `ChecksumAddress` for ERC-55 formatted addresses, `HexAddress` for general hex-encoded addresses. [9]
ABI
```
from eth_typing.abi import ABI
```
ABI-related types are located in the `eth_typing.abi` submodule. [1, 9]

Quickstart

Demonstrates importing and using `Address`, `ChecksumAddress`, and `HexStr` for type hinting. This example simplifies address processing as `eth-typing` focuses solely on type definitions, not implementation logic.

from eth_typing.evm import Address, ChecksumAddress
from eth_typing.encoding import HexStr

def process_ethereum_address(address: Address) -> ChecksumAddress:
    # In a real application, you would perform checksum validation
    # or other address-related logic here.
    # For this example, we'll just cast it for demonstration.
    # eth-utils or web3.py typically handle checksumming.
    if not isinstance(address, str) or not address.startswith('0x'):
        raise ValueError('Invalid address format')
    # Simulate a checksummed address return
    return ChecksumAddress(address.lower()) # Simplified for quickstart

my_raw_address: Address = Address('0x742d35Cc6634C0532925a3b844Bc454e4438f444')
checksum_addr: ChecksumAddress = process_ethereum_address(my_raw_address)

print(f'Processed Address: {checksum_addr}')

def get_hex_string_length(hex_str: HexStr) -> int:
    return len(hex_str)

my_hex_string: HexStr = HexStr('0xabcdef123456')
print(f'Hex string length: {get_hex_string_length(my_hex_string)}')

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