|
|
# coding: utf-8
|
|
|
"""
|
|
|
Utilities for dealing with text encodings
|
|
|
"""
|
|
|
|
|
|
#-----------------------------------------------------------------------------
|
|
|
# Copyright (C) 2008-2012 The IPython Development Team
|
|
|
#
|
|
|
# Distributed under the terms of the BSD License. The full license is in
|
|
|
# the file COPYING, distributed as part of this software.
|
|
|
#-----------------------------------------------------------------------------
|
|
|
|
|
|
#-----------------------------------------------------------------------------
|
|
|
# Imports
|
|
|
#-----------------------------------------------------------------------------
|
|
|
import sys
|
|
|
import locale
|
|
|
import warnings
|
|
|
|
|
|
# to deal with the possibility of sys.std* not being a stream at all
|
|
|
def get_stream_enc(stream, default=None):
|
|
|
"""Return the given stream's encoding or a default.
|
|
|
|
|
|
There are cases where ``sys.std*`` might not actually be a stream, so
|
|
|
check for the encoding attribute prior to returning it, and return
|
|
|
a default if it doesn't exist or evaluates as False. ``default``
|
|
|
is None if not provided.
|
|
|
"""
|
|
|
if not hasattr(stream, 'encoding') or not stream.encoding:
|
|
|
return default
|
|
|
else:
|
|
|
return stream.encoding
|
|
|
|
|
|
# Less conservative replacement for sys.getdefaultencoding, that will try
|
|
|
# to match the environment.
|
|
|
# Defined here as central function, so if we find better choices, we
|
|
|
# won't need to make changes all over IPython.
|
|
|
def getdefaultencoding(prefer_stream=True):
|
|
|
"""Return IPython's guess for the default encoding for bytes as text.
|
|
|
|
|
|
If prefer_stream is True (default), asks for stdin.encoding first,
|
|
|
to match the calling Terminal, but that is often None for subprocesses.
|
|
|
|
|
|
Then fall back on locale.getpreferredencoding(),
|
|
|
which should be a sensible platform default (that respects LANG environment),
|
|
|
and finally to sys.getdefaultencoding() which is the most conservative option,
|
|
|
and usually ASCII on Python 2 or UTF8 on Python 3.
|
|
|
"""
|
|
|
enc = None
|
|
|
if prefer_stream:
|
|
|
enc = get_stream_enc(sys.stdin)
|
|
|
if not enc or enc=='ascii':
|
|
|
try:
|
|
|
# There are reports of getpreferredencoding raising errors
|
|
|
# in some cases, which may well be fixed, but let's be conservative here.
|
|
|
enc = locale.getpreferredencoding()
|
|
|
except Exception:
|
|
|
pass
|
|
|
enc = enc or sys.getdefaultencoding()
|
|
|
# On windows `cp0` can be returned to indicate that there is no code page.
|
|
|
# Since cp0 is an invalid encoding return instead cp1252 which is the
|
|
|
# Western European default.
|
|
|
if enc == 'cp0':
|
|
|
warnings.warn(
|
|
|
"Invalid code page cp0 detected - using cp1252 instead."
|
|
|
"If cp1252 is incorrect please ensure a valid code page "
|
|
|
"is defined for the process.", RuntimeWarning)
|
|
|
return 'cp1252'
|
|
|
return enc
|
|
|
|
|
|
DEFAULT_ENCODING = getdefaultencoding()
|
|
|
|
