cchecksum

0.4.3 · active · verified Thu Apr 16

cchecksum is a Python library that provides an approximately 18x faster, C-implemented drop-in replacement for `eth_utils.to_checksum_address`. It ensures full API compatibility, raising the exact same exceptions as the original `eth_utils` function. Currently at version 0.4.3, the library is actively maintained with a focus on performance optimizations and broad platform compatibility through pre-built wheels.

Common errors

```
ModuleNotFoundError: No module named 'cchecksum'
```
cause The cchecksum package is not installed in the current Python environment.

fix Run `pip install cchecksum`.
```
ImportError: cannot import name 'to_checksum_address' from 'cchecksum'
```
cause Incorrect import statement or a damaged installation. The primary function is `to_checksum_address`.

fix Verify the import statement is exactly `from cchecksum import to_checksum_address`. If it persists, try reinstalling `cchecksum`.
```
ModuleNotFoundError: No module named 'eth_hash'
```
cause cchecksum relies on `eth-hash` for its internal hashing, and `eth-hash` was not installed as a dependency, potentially due to an old `pip` or incomplete install prior to `v0.3.5`.

fix Ensure `eth-hash` is installed: `pip install eth-hash`. Reinstalling `cchecksum` (`pip install cchecksum`) should also pull its dependencies.
```
error: Microsoft Visual C++ 14.0 or greater is required. Get it with "Microsoft C++ Build Tools": ...
```
cause The installation failed because a C compiler is needed to compile cchecksum's C/Cython extensions, and a pre-built wheel was not available for the specific environment.

fix Install the required C/C++ build tools for your operating system. For Windows, download and install 'Microsoft C++ Build Tools'. For Linux, install development packages like `build-essential` (Debian/Ubuntu) or `gcc` (CentOS/Fedora).

Warnings

breaking Python 3.8 support was dropped in cchecksum v0.4.0. Users on Python 3.8 will need to use an older version of cchecksum (pre-0.4.0) or upgrade their Python interpreter to 3.9 or newer.
Fix: Upgrade Python to 3.9+ or pin `cchecksum<0.4.0` in your dependencies.
gotcha To benefit from cchecksum's performance improvements, you must explicitly import `to_checksum_address` from `cchecksum`. If `eth_utils.to_checksum_address` remains in your code, you will continue to use the slower Python-based implementation.
Fix: Replace `from eth_utils import to_checksum_address` with `from cchecksum import to_checksum_address` in your codebase.
gotcha Installation may require a C compiler if pre-compiled wheels are not available for your specific Python version and operating system. The core logic is implemented in C and Cython.
Fix: Ensure you have a C compiler installed (e.g., `build-essential` on Linux, Microsoft C++ Build Tools on Windows) if encountering build errors during installation.

Install

pip install cchecksum Install stable version

Imports

to_checksum_address
wrong:
```
from eth_utils import to_checksum_address
```
correct:
```
from cchecksum import to_checksum_address
```
cchecksum is a drop-in replacement; using the eth_utils import will not utilize the performance benefits of cchecksum.

Quickstart

This quickstart demonstrates how to import and use the `to_checksum_address` function from `cchecksum` with both hexadecimal string and raw bytes inputs, producing an EIP-55 checksummed Ethereum address.

from cchecksum import to_checksum_address
from binascii import unhexlify

# Convert a lowercase hex string with 0x prefix
address_hex_lower = "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2"
checksummed_address = to_checksum_address(address_hex_lower)
print(f"Original: {address_hex_lower}")
print(f"Checksummed: {checksummed_address}")

# Convert bytes input (must be 20 bytes long)
address_bytes = unhexlify(address_hex_lower[2:]) # Removes '0x' prefix
checksummed_bytes_address = to_checksum_address(address_bytes)
print(f"Original Bytes: {address_bytes.hex()}")
print(f"Checksummed Bytes: {checksummed_bytes_address}")

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