# $Id: _compat.py 7486 2012-07-11 12:25:14Z milde $
# Author: Georg Brandl <georg@python.org>
# Copyright: This module has been placed in the public domain.
"""
Python 2/3 compatibility definitions.
This module currently provides the following helper symbols:
* bytes (name of byte string type; str in 2.x, bytes in 3.x)
* b (function converting a string literal to an ASCII byte string;
can be also used to convert a Unicode string into a byte string)
* u_prefix (unicode repr prefix: 'u' in 2.x, '' in 3.x)
(Required in docutils/test/test_publisher.py)
* BytesIO (a StringIO class that works with bytestrings)
"""
import sys
if sys.version_info < (3,0):
b = bytes = str
u_prefix = 'u'
from io import StringIO as BytesIO
else:
import builtins
bytes = builtins.bytes
u_prefix = ''
[docs] def b(s):
if isinstance(s, str):
return s.encode('latin1')
elif isinstance(s, bytes):
return s
else:
raise TypeError("Invalid argument %r for b()" % (s,))
# using this hack since 2to3 "fixes" the relative import
# when using ``from io import BytesIO``
BytesIO = __import__('io').BytesIO
if sys.version_info < (2,5):
import builtins
def __import__(name, globals={}, locals={}, fromlist=[], level=-1):
"""Compatibility definition for Python 2.4.
Silently ignore the `level` argument missing in Python < 2.5.
"""
# we need the level arg because the default changed in Python 3.3
return builtins.__import__(name, globals, locals, fromlist)