1.2. binascii — Convert between binary and ASCII

The binascii module contains a number of methods to convert between binary and various ASCII-encoded binary representations.

---

binascii.a2b_base64(string)

Convert a block of base64 data back to binary and return the binary data. More than one line may be passed at a time.

binascii.b2a_base64(data)

Convert binary data to a line of ASCII characters in base64 coding. The return value is the converted line, including a newline char. The newline is added because the original use case for this function was to feed it a series of 57 byte input lines to get output lines that conform to the MIME-base64 standard. Otherwise the output conforms to RFC 3548.

binascii.crc32(data[, value])

Compute CRC-32, the 32-bit checksum of data, starting with an initial CRC of value. The default initial CRC is zero. The algorithm is consistent with the ZIP file checksum. Since the algorithm is designed for use as a checksum algorithm, it is not suitable for use as a general hash algorithm. Use as follows:

>>> binascii.crc32(b"hello world")
222957957
>>> crc = binascii.crc32(b"hello")
>>> binascii.crc32(b" world", crc)
222957957

binascii.hexlify(data)

Return the hexadecimal representation of the binary data. Every byte of data is converted into the corresponding 2-digit hex representation. The returned bytes object is therefore twice as long as the length of data.

binascii.unhexlify(hexstr)

Return the binary data represented by the hexadecimal string hexstr. This function is the inverse of hexlify(). hexstr must contain an even number of hexadecimal digits (which can be upper or lower case), otherwise an Error exception is raised.