This module provides data encoding and decoding as specified in RFC 3548. This standard defines the Base16, Base32, and Base64 algorithms for encoding and decoding arbitrary binary strings into text strings that can be safely sent by email, used as parts of URLs, or included as part of an HTTP POST request. The encoding algorith is not the same as the uuencode program.
There are two interfaces provided by this module. The modern interface supports encoding and decoding string objects using all three alphabets. The legacy interface provides for encoding and decoding to and from file-like objects as well as strings, but only using the Base64 standard alphabet.
The modern interface provides:
s[, altchars]) |
s is the string to encode. Optional altchars must be a
string of at least length 2 (additional characters are ignored) which
specifies an alternative alphabet for the +
and /
characters. This allows an application to e.g. generate URL or
filesystem safe Base64 strings. The default is None
, for which
the standard Base64 alphabet is used.
The encoded string is returned.
s[, altchars]) |
s is the string to decode. Optional altchars must be a
string of at least length 2 (additional characters are ignored) which
specifies the alternative alphabet used instead of the +
and
/
characters.
The decoded string is returned. A TypeError is raised if s were incorrectly padded or if there are non-alphabet characters present in the string.
s) |
s) |
s) |
-
instead of +
and _
instead of /
in the
standard Base64 alphabet.
s) |
-
instead of +
and _
instead of /
in the
standard Base64 alphabet.
s) |
s[, casefold[, map01]]) |
s is the string to decode. Optional casefold is a flag
specifying whether a lowercase alphabet is acceptable as input. For
security purposes, the default is False
.
RFC 3548 allows for optional mapping of the digit 0 (zero) to the
letter O (oh), and for optional mapping of the digit 1 (one) to either
the letter I (eye) or letter L (el). The optional argument
map01 when not None
, specifies which letter the digit 1 should
be mapped to (when map01 is not None, the digit 0 is always
mapped to the letter O). For security purposes the default is
None
, so that 0 and 1 are not allowed in the input.
The decoded string is returned. A TypeError is raised if s were incorrectly padded or if there are non-alphabet characters present in the string.
s) |
s is the string to encode. The encoded string is returned.
s[, casefold]) |
s is the string to decode. Optional casefold is a flag
specifying whether a lowercase alphabet is acceptable as input. For
security purposes, the default is False
.
The decoded string is returned. A TypeError is raised if s were incorrectly padded or if there are non-alphabet characters present in the string.
The legacy interface:
input, output) |
input.read()
returns an empty string.
s) |
input, output) |
input.read()
returns an empty string. encode()
returns the encoded data plus a trailing newline character
('\n'
).
s) |
'\n'
).
See Also: