AnyCRC Library

2.0.0 · active · verified Fri Apr 17

anycrc is a Python library providing extremely fast CRC (Cyclic Redundancy Check) calculations. It leverages hardware acceleration on Intel (SSE4.2, AVX512) and Arm (ARMv8-CRC) processors for significant speedups, claiming up to 10x faster than previous versions. The current version is 2.0.0, maintaining an active development pace with notable updates for performance and Python version compatibility.

Common errors

```
AttributeError: module 'anycrc.crc' has no attribute 'crc32_mpeg2'
```
cause Attempting to access a CRC algorithm directly from the `anycrc` module or as a static method, when it's an attribute of the `crc` submodule and requires instantiation.

fix Ensure you are importing `crc` as `from anycrc import crc` and then instantiating the specific CRC algorithm, e.g., `c = crc.crc32_mpeg2()`.
```
TypeError: calc() missing 1 required positional argument: 'data'
```
cause This error occurs if you try to call the `calc()` method on the CRC algorithm class itself (e.g., `crc.crc32_mpeg2.calc(data)`) instead of on an instantiated object of that class.

fix First create an instance of the CRC algorithm: `c = crc.crc32_mpeg2()`, then call `calc()` on that instance: `checksum = c.calc(data)`.
```
TypeError: argument must be a bytes-like object, not str
```
cause The `calc()` method expects binary data (bytes or bytearray) for CRC calculation, but a string was provided.

fix Convert your string to bytes using `.encode()` or prefix it with `b` (e.g., `b"my string"`) before passing it to `calc()`.

Warnings

breaking Version 2.0.0 switched the underlying CRC implementation from `crcany` to a custom library and introduced significant API changes due to a new object caching mechanism (introduced in 1.3.0). Direct calls to global functions like `anycrc.crc32()` are no longer supported.
Fix: Update your code to instantiate CRC algorithms as objects (e.g., `c = crc.crc32_mpeg2()`) and then call the `calc()` method on the instance (e.g., `c.calc(data)`). Refer to the official documentation or GitHub README for updated API usage.
deprecated Python 3.7 support was officially dropped in version 1.3.5. Users running Python 3.7 will not be able to install or use anycrc versions 1.3.5 or newer.
Fix: Upgrade your Python environment to version 3.8 or newer to use current `anycrc` releases.
gotcha While anycrc provides significant speedups through hardware acceleration on compatible Intel and Arm CPUs, performance will degrade to a software implementation if the necessary CPU features (e.g., SSE4.2, AVX512 for Intel; ARMv8-CRC for Arm) are not present.
Fix: No action is strictly required as the library gracefully falls back. However, for maximum performance, ensure the application runs on hardware with the specified CRC acceleration instructions. No user-level configuration is available to force hardware acceleration.

Install

pip install anycrc Install latest version

Imports

crc
```
from anycrc import crc
```

Quickstart

Initialize a CRC algorithm object and then use its `calc()` method to compute the checksum for byte-like data.

from anycrc import crc

# Calculate CRC32 MPEG2
c32 = crc.crc32_mpeg2()
checksum_mpeg2 = c32.calc(b"Hello, World!")
print(f"CRC32 MPEG2 of 'Hello, World!': {checksum_mpeg2:08x}")

# Calculate CRC16 CCITT
c16 = crc.crc16_ccitt()
checksum_ccitt = c16.calc(b"Another string")
print(f"CRC16 CCITT of 'Another string': {checksum_ccitt:04x}")

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