compat.py   [plain text]

# -*- test-case-name: twisted.test.test_compat -*-
#
# Twisted, the Framework of Your Internet
# Copyright (C) 2001 Matthew W. Lefkowitz
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of version 2.1 of the GNU Lesser General Public
# License as published by the Free Software Foundation.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

"""
Compatability module to provide backwards compatability
for useful Python features.

This is mainly for use of internal Twisted code. We encourage you to use
the latest version of Python directly from your code, if possible.
"""

import sys, types, socket, struct, __builtin__, exceptions

#elif sys.version_info[:2] == (2, 2):
#    def dict(*arg, **kwargs):
#        d = types.DictType(*arg)
#        d.update(kwargs)
#        return d
#    dict.__doc__ = _dict_doc
#    __builtin__.dict = dict


if sys.version_info[:3] == (2, 2, 0):
    __builtin__.True = (1 == 1)
    __builtin__.False = (1 == 0)
    def bool(value):
        """Demote a value to 0 or 1, depending on its truth value

        This is not to be confused with types.BooleanType, which is
        way too hard to duplicate in 2.1 to be worth the trouble.
        """
        return not not value
    __builtin__.bool = bool
    del bool


if not hasattr(socket, 'inet_pton'):
    def inet_pton(af, addr):
        if af == socket.AF_INET:
            parts = map(int, addr.split('.'))
            return struct.pack('!BBBB', *parts)
        elif af == getattr(socket, 'AF_INET6', None):
            parts = addr.split(':')
            elide = parts.count('')
            if elide == 3:
                return '\x00' * 16
            elif elide == 2:
                i = parts.index('')
                parts[i:i+2] = ['0'] * (10 - len(parts))
            elif elide == 1:
                i = parts.index('')
                parts[i:i+1] = ['0'] * (9 - len(parts))
            parts = [int(x, 16) for x in parts]
            return struct.pack('!HHHHHHHH', *parts)
        else:
            raise socket.error(97, 'Address family not supported by protocol')

    def inet_ntop(af, addr):
        if af == socket.AF_INET:
            parts = struct.unpack('!BBBB', addr)
            return '.'.join(map(str, parts))
        elif af == getattr(socket, 'AF_INET6', None):
            parts = struct.unpack('!HHHHHHHH', addr)
            return ':'.join([hex(x)[2:] for x in parts])
        else:
            raise socket.error(97, 'Address family not supported by protocol')

    socket.inet_pton = inet_pton
    socket.inet_ntop = inet_ntop

if sys.version_info[:3] in ((2, 2, 0), (2, 2, 1)):
    import string
    def lstrip(s, c=string.whitespace):
        while s and s[0] in c:
            s = s[1:]
        return s
    def rstrip(s, c=string.whitespace):
        while s and s[-1] in c:
            s = s[:-1]
        return s
    def strip(s, c=string.whitespace, l=lstrip, r=rstrip):
        return l(r(s, c), c)
    
    object.__setattr__(str, 'lstrip', lstrip)
    object.__setattr__(str, 'rstrip', rstrip)
    object.__setattr__(str, 'strip', strip)

import types, socket, struct

# Compatibility with compatibility
# We want to get rid of these as quickly as we can
# Unfortunately some code imports them by name

True = True
False = False
bool = bool
dict = dict
StopIteration = StopIteration
iter = iter
isinstance = isinstance