Victor Stinner e49e812900 Add utilities for base64
Writing a code using the base64 module (of the Python standard
library) working on Python 2.7 and 3.4 requires many checks on the
input and/or output type:

* base64.b64encode() only accepts byte string: text must be
  explicitly encoded to ASCII
* base64.b64decode() returns bytes: output must be decoded from UTF-8
  when text is expected

This change adds two pairs of encode/decode functions:

* encode_as_bytes(), decode_as_bytes(): always return the result as
  a byte string
* encode_as_text(), decode_as_text(): always return the result as a
  text string

Encode functions accept text: text is encoded to UTF-8 by default,
but the encoding is configurable.

Decode functions accept text: text is decoded from ASCII.

decode_as_text() decodes the result from UTF-8 by default, but again
the encoding is configurable.


The new submodule is called "base64" to be able to replace:

    import base64

with:

    from oslo_serialization import base64

If the base64 module of the stdlib is needed, it can be imported as a
different name. Example:

    import base64 as std_base64


The encoding example:

    if isinstance(text, six.text_type):
       text = text.encode('utf-8')
    text_b64 = base64.b64encode(text)
    text_b64 = text_b64.decode('ascii')

can be replaced with:

    text_b64 = base64.encode_as_text(text)


The decoding example:

    if isinstance(encoded, six.text_type):
       encoded = encoded.decode('ascii')
    text = base64.b64decode(encoded)
    text = text.decode('utf-8')

can be replaced with:

    text = base64.decode_as_text(text)

Change-Id: Icf8df9c947bc0c5f4838508b756ed8f53efd9fc4
2015-10-01 14:32:29 +00:00

57 lines
2.2 KiB
Python

# Copyright 2015 Red Hat
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
from oslo_serialization import base64
from oslotest import base as test_base
class Base64Tests(test_base.BaseTestCase):
def test_encode_as_bytes(self):
self.assertEqual(base64.encode_as_bytes(b'text'),
b'dGV4dA==')
self.assertEqual(base64.encode_as_bytes(u'text'),
b'dGV4dA==')
self.assertEqual(base64.encode_as_bytes(u'e:\xe9'),
b'ZTrDqQ==')
self.assertEqual(base64.encode_as_bytes(u'e:\xe9', encoding='latin1'),
b'ZTrp')
def test_encode_as_text(self):
self.assertEqual(base64.encode_as_text(b'text'),
u'dGV4dA==')
self.assertEqual(base64.encode_as_text(u'text'),
u'dGV4dA==')
self.assertEqual(base64.encode_as_text(u'e:\xe9'),
u'ZTrDqQ==')
self.assertEqual(base64.encode_as_text(u'e:\xe9', encoding='latin1'),
u'ZTrp')
def test_decode_as_bytes(self):
self.assertEqual(base64.decode_as_bytes(b'dGV4dA=='),
b'text')
self.assertEqual(base64.decode_as_bytes(u'dGV4dA=='),
b'text')
def test_decode_as_text(self):
self.assertEqual(base64.decode_as_text(b'dGV4dA=='),
u'text')
self.assertEqual(base64.decode_as_text(u'dGV4dA=='),
u'text')
self.assertEqual(base64.decode_as_text(u'ZTrDqQ=='),
u'e:\xe9')
self.assertEqual(base64.decode_as_text(u'ZTrp', encoding='latin1'),
u'e:\xe9')