binascii

Binascii is a Python standard library module that provides helpers for converting binary data to and from various ASCII representations. It is used when decoding or encoding binary streams for storage, transmission, or interoperability with text-based formats. The module focuses on low-level, byte-oriented conversions and is widely used in data processing, networking, and cryptographic tooling.

Common operations in binascii involve converting between binary data and textual encodings. Hexadecimal conversions are performed with hexlify and unhexlify, which translate binary data to hex text and back. For base64, the module offers b2a_base64 and a2b_base64 to encode and decode, respectively. Other encodings supported through binascii include uuencode (b2a_uu and a2b_uu) and quoted-printable (b2a_qp and a2b_qp). In addition, binascii provides a function for a CRC-16 CCITT calculation, crc_hqx, which can be used for simple data integrity checks.

The functions generally accept and return byte-oriented data and raise binascii.Error on invalid input. The module is designed for performance and fine-grained control over encoding and decoding tasks that may not be as straightforward with higher-level modules. While many common encodings can be handled by higher-level libraries, binascii remains valuable for direct, low-level conversions and for working with legacy data formats that mix binary and ASCII representations.

Overall, binascii serves as a compact toolkit for binary-ASCII transformations within Python programs, offering a focused set of utilities aligned with traditional encoding schemes and low-level data manipulation. It is compatible with both Python 2 and Python 3, though usage patterns are more commonly encountered in modern Python code dealing with binary I/O and protocol parsing.