1# Copyright 2015 Google Inc. All Rights Reserved. 2# 3# Licensed under the Apache License, Version 2.0 (the "License"); 4# you may not use this file except in compliance with the License. 5# You may obtain a copy of the License at 6# 7# http://www.apache.org/licenses/LICENSE-2.0 8# 9# Unless required by applicable law or agreed to in writing, software 10# distributed under the License is distributed on an "AS IS" BASIS, 11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12# See the License for the specific language governing permissions and 13# limitations under the License. 14"""Utilities for Python2 / Python3 compatibility.""" 15 16import io 17import os 18import sys 19 20PY3 = sys.version_info[0] >= 3 21PY36 = sys.version_info[0] >= 3 and sys.version_info[1] >= 6 22 23if PY3: 24 StringIO = io.StringIO 25 BytesIO = io.BytesIO 26 27 import codecs 28 29 def open_with_encoding(filename, mode, encoding, newline=''): # pylint: disable=unused-argument 30 return codecs.open(filename, mode=mode, encoding=encoding) 31 32 import functools 33 lru_cache = functools.lru_cache 34 35 range = range 36 ifilter = filter 37 38 def raw_input(): 39 wrapper = io.TextIOWrapper(sys.stdin.buffer, encoding='utf-8') 40 return wrapper.buffer.raw.readall().decode('utf-8') 41 42 import configparser 43 44 # Mappings from strings to booleans (such as '1' to True, 'false' to False, 45 # etc.) 46 CONFIGPARSER_BOOLEAN_STATES = configparser.ConfigParser.BOOLEAN_STATES 47else: 48 import __builtin__ 49 import cStringIO 50 StringIO = BytesIO = cStringIO.StringIO 51 52 open_with_encoding = io.open 53 54 # Python 2.7 doesn't have a native LRU cache, so do nothing. 55 def lru_cache(maxsize=128, typed=False): 56 57 def fake_wrapper(user_function): 58 return user_function 59 60 return fake_wrapper 61 62 range = xrange 63 64 from itertools import ifilter 65 raw_input = raw_input 66 67 import ConfigParser as configparser 68 CONFIGPARSER_BOOLEAN_STATES = configparser.ConfigParser._boolean_states # pylint: disable=protected-access 69 70 71def EncodeAndWriteToStdout(s, encoding='utf-8'): 72 """Encode the given string and emit to stdout. 73 74 The string may contain non-ascii characters. This is a problem when stdout is 75 redirected, because then Python doesn't know the encoding and we may get a 76 UnicodeEncodeError. 77 78 Arguments: 79 s: (string) The string to encode. 80 encoding: (string) The encoding of the string. 81 """ 82 if PY3: 83 sys.stdout.buffer.write(s.encode(encoding)) 84 elif sys.platform == 'win32': 85 # On python 2 and Windows universal newline transformation will be in 86 # effect on stdout. Python 2 will not let us avoid the easily because 87 # it happens based on whether the file handle is opened in O_BINARY or 88 # O_TEXT state. However we can tell Windows itself to change the current 89 # mode, and python 2 will follow suit. However we must take care to change 90 # the mode on the actual external stdout not just the current sys.stdout 91 # which may have been monkey-patched inside the python environment. 92 import msvcrt # pylint: disable=g-import-not-at-top 93 if sys.__stdout__ is sys.stdout: 94 msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY) 95 sys.stdout.write(s.encode(encoding)) 96 else: 97 sys.stdout.write(s.encode(encoding)) 98 99 100if PY3: 101 basestring = str 102 unicode = str # pylint: disable=redefined-builtin,invalid-name 103else: 104 basestring = basestring 105 106 def unicode(s): # pylint: disable=invalid-name 107 """Force conversion of s to unicode.""" 108 return __builtin__.unicode(s, 'utf-8') 109 110 111# In Python 3.2+, readfp is deprecated in favor of read_file, which doesn't 112# exist in Python 2 yet. To avoid deprecation warnings, subclass ConfigParser to 113# fix this - now read_file works across all Python versions we care about. 114class ConfigParser(configparser.ConfigParser): 115 if not PY3: 116 117 def read_file(self, fp, source=None): 118 self.readfp(fp, filename=source) 119