The binascii module contains a number of methods to convert
between binary and various ASCII-encoded binary
representations. Normally, you will not use these functions directly
but use wrapper modules like uuor
binhexinstead, this module solely
exists because bit-manipulation of large amounts of data is slow in
The binascii module defines the following functions:
Convert binary data to a line of ASCII characters in base64 coding.
The return value is the converted line, including a newline char.
The length of data should be at most 57 to adhere to the base64
Convert a block of quoted-printable data back to binary and return the
binary data. More than one line may be passed at a time.
If the optional argument header is present and true, underscores
will be decoded as spaces.
Convert binary data to a line(s) of ASCII characters in
quoted-printable encoding. The return value is the converted line(s).
If the optional argument quotetabs is present and true, all tabs
and spaces will be encoded. If the optional argument header is
present and true, spaces will be encoded as underscores per RFC1522.
If the optional argument header is present and false, newline
characters will be encoded as well, otherwise linefeed conversion might
corrupt the binary data stream.
Convert binhex4 formatted ASCII data to binary, without doing
RLE-decompression. The string should contain a complete number of
binary bytes, or (in case of the last portion of the binhex4 data)
have the remaining bits zero.
Perform RLE-decompression on the data, as per the binhex4
standard. The algorithm uses 0x90 after a byte as a repeat
indicator, followed by a count. A count of 0 specifies a byte
value of 0x90. The routine returns the decompressed data,
unless data input data ends in an orphaned repeat indicator, in which
case the Incomplete exception is raised.
Compute CRC-32, the 32-bit checksum of data, starting with an initial
crc. This 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:
print binascii.crc32("hello world")
# Or, in two pieces:
crc = binascii.crc32("hello")
crc = binascii.crc32(" world", crc)
Return the hexadecimal representation of the binary data. Every
byte of data is converted into the corresponding 2-digit hex
representation. The resulting string is therefore twice as long as
the length of data.
Return the binary data represented by the hexadecimal string
hexstr. This function is the inverse of b2a_hex().
hexstr must contain an even number of hexadecimal digits (which
can be upper or lower case), otherwise a TypeError is