email.base64mime

Base64 content transfer encoding per RFCs 2045-2047.

This module handles the content transfer encoding method defined in RFC 2045
to encode arbitrary 8-bit data using the three 8-bit bytes in four 7-bit
characters encoding known as Base64.

It is used in the MIME standards for email to attach images, audio, and text
using some 8-bit character sets to messages.

This module provides an interface to encode and decode both headers and bodies
with Base64 encoding.

RFC 2045 defines a method for including character set information in an
`encoded-word' in a header.  This method is commonly used for 8-bit real names
in To:, From:, Cc:, etc. fields, as well as Subject: lines.

This module does not do the line wrapping or end-of-line character conversion
necessary for proper internationalized headers; it only does dumb encoding and
decoding.  To deal with the various line wrapping issues, use the email.header
module.

Functions

a2b_base64

a2b_base64(data, /)

  Decode a line of base64 data.

b2a_base64

b2a_base64(data, /, *, newline=True)

  Base64-code line of data.

b64encode

b64encode(s, altchars=None)

  Encode the bytes-like object s using Base64 and return a bytes object.

      Optional altchars should be a byte string of length 2 which specifies an
      alternative alphabet for the '+' and '/' characters.  This allows an
      application to e.g. generate url or filesystem safe Base64 strings.

body_decode

decode(string)

  Decode a raw base64 string, returning a bytes object.

      This function does not parse a full MIME header value encoded with
      base64 (like =?iso-8859-1?b?bmloISBuaWgh?=) -- please use the high
      level email.header class for that functionality.

body_encode

body_encode(s, maxlinelen=76, eol='\n')

  Encode a string with base64.

      Each line will be wrapped at, at most, maxlinelen characters (defaults to
      76 characters).

      Each line of encoded text will end with eol, which defaults to "\n".  Set
      this to "\r\n" if you will be using the result of this function directly
      in an email.

decode

decode(string)

  Decode a raw base64 string, returning a bytes object.

      This function does not parse a full MIME header value encoded with
      base64 (like =?iso-8859-1?b?bmloISBuaWgh?=) -- please use the high
      level email.header class for that functionality.

decodestring

decode(string)

  Decode a raw base64 string, returning a bytes object.

      This function does not parse a full MIME header value encoded with
      base64 (like =?iso-8859-1?b?bmloISBuaWgh?=) -- please use the high
      level email.header class for that functionality.

header_encode

header_encode(header_bytes, charset='iso-8859-1')

  Encode a single header line with Base64 encoding in a given charset.

      charset names the character set to use to encode the header.  It defaults
      to iso-8859-1.  Base64 encoding is defined in RFC 2045.

header_length

header_length(bytearray)

  Return the length of s when it is encoded with base64.

Other members

CRLF = '\r\n'

EMPTYSTRING = ''

MISC_LEN = 7

NL = '\n'