qtpy/py3compat.py

   1 # -*- coding: utf-8 -*-
   2 #
   3 # Copyright © 2012-2013 Pierre Raybaut
   4 # Licensed under the terms of the MIT License
   5 # (see spyderlib/__init__.py for details)
   6
   7 """
   8 spyderlib.py3compat
   9 -------------------
  10
  11 Transitional module providing compatibility functions intended to help
  12 migrating from Python 2 to Python 3.
  13
  14 This module should be fully compatible with:
  15     * Python >=v2.6
  16     * Python 3
  17 """
  18
  19 from __future__ import print_function
  20
  21 import sys
  22 import os
  23
  24 PY2 = sys.version_info[0] == 2
  25 PY3 = sys.version_info[0] == 3
  26 PY33 = PY3 and sys.version_info[1] >= 3
  27
  28
  29 # =============================================================================
  30 # Data types
  31 # =============================================================================
  32 if PY2:
  33     # Python 2
  34     TEXT_TYPES = (str, unicode)
  35     INT_TYPES = (int, long)
  36 else:
  37     # Python 3
  38     TEXT_TYPES = (str,)
  39     INT_TYPES = (int,)
  40 NUMERIC_TYPES = tuple(list(INT_TYPES) + [float, complex])
  41
  42
  43 # =============================================================================
  44 # Renamed/Reorganized modules
  45 # =============================================================================
  46 if PY2:
  47     # Python 2
  48     import __builtin__ as builtins
  49     import ConfigParser as configparser
  50     try:
  51         import _winreg as winreg
  52     except ImportError:
  53         pass
  54     from sys import maxint as maxsize
  55     try:
  56         import CStringIO as io
  57     except ImportError:
  58         import StringIO as io
  59     try:
  60         import cPickle as pickle
  61     except ImportError:
  62         import pickle
  63     from UserDict import DictMixin as MutableMapping
  64     import thread as _thread
  65     import repr as reprlib
  66 else:
  67     # Python 3
  68     import builtins
  69     import configparser
  70     try:
  71         import winreg
  72     except ImportError:
  73         pass
  74     from sys import maxsize
  75     import io
  76     import pickle
  77     if PY33:
  78         from collections.abc import MutableMapping
  79     else:
  80         from collections import MutableMapping
  81     import _thread
  82     import reprlib
  83
  84
  85 # =============================================================================
  86 # Strings
  87 # =============================================================================
  88 if PY2:
  89     # Python 2
  90     import codecs
  91
  92     def u(obj):
  93         """Make unicode object"""
  94         return codecs.unicode_escape_decode(obj)[0]
  95 else:
  96     # Python 3
  97     def u(obj):
  98         """Return string as it is"""
  99         return obj
 100
 101
 102 def is_text_string(obj):
 103     """Return True if `obj` is a text string, False if it is anything else,
 104     like binary data (Python 3) or QString (Python 2, PyQt API #1)"""
 105     if PY2:
 106         # Python 2
 107         return isinstance(obj, basestring)
 108     else:
 109         # Python 3
 110         return isinstance(obj, str)
 111
 112
 113 def is_binary_string(obj):
 114     """Return True if `obj` is a binary string, False if it is anything else"""
 115     if PY2:
 116         # Python 2
 117         return isinstance(obj, str)
 118     else:
 119         # Python 3
 120         return isinstance(obj, bytes)
 121
 122
 123 def is_string(obj):
 124     """Return True if `obj` is a text or binary Python string object,
 125     False if it is anything else, like a QString (Python 2, PyQt API #1)"""
 126     return is_text_string(obj) or is_binary_string(obj)
 127
 128
 129 def is_unicode(obj):
 130     """Return True if `obj` is unicode"""
 131     if PY2:
 132         # Python 2
 133         return isinstance(obj, unicode)
 134     else:
 135         # Python 3
 136         return isinstance(obj, str)
 137
 138
 139 def to_text_string(obj, encoding=None):
 140     """Convert `obj` to (unicode) text string"""
 141     if PY2:
 142         # Python 2
 143         if encoding is None:
 144             return unicode(obj)
 145         else:
 146             return unicode(obj, encoding)
 147     else:
 148         # Python 3
 149         if encoding is None:
 150             return str(obj)
 151         elif isinstance(obj, str):
 152             # In case this function is not used properly, this could happen
 153             return obj
 154         else:
 155             return str(obj, encoding)
 156
 157
 158 def to_binary_string(obj, encoding=None):
 159     """Convert `obj` to binary string (bytes in Python 3, str in Python 2)"""
 160     if PY2:
 161         # Python 2
 162         if encoding is None:
 163             return str(obj)
 164         else:
 165             return obj.encode(encoding)
 166     else:
 167         # Python 3
 168         return bytes(obj, 'utf-8' if encoding is None else encoding)
 169
 170
 171 # =============================================================================
 172 # Function attributes
 173 # =============================================================================
 174 def get_func_code(func):
 175     """Return function code object"""
 176     if PY2:
 177         # Python 2
 178         return func.func_code
 179     else:
 180         # Python 3
 181         return func.__code__
 182
 183
 184 def get_func_name(func):
 185     """Return function name"""
 186     if PY2:
 187         # Python 2
 188         return func.func_name
 189     else:
 190         # Python 3
 191         return func.__name__
 192
 193
 194 def get_func_defaults(func):
 195     """Return function default argument values"""
 196     if PY2:
 197         # Python 2
 198         return func.func_defaults
 199     else:
 200         # Python 3
 201         return func.__defaults__
 202
 203
 204 # =============================================================================
 205 # Special method attributes
 206 # =============================================================================
 207 def get_meth_func(obj):
 208     """Return method function object"""
 209     if PY2:
 210         # Python 2
 211         return obj.im_func
 212     else:
 213         # Python 3
 214         return obj.__func__
 215
 216
 217 def get_meth_class_inst(obj):
 218     """Return method class instance"""
 219     if PY2:
 220         # Python 2
 221         return obj.im_self
 222     else:
 223         # Python 3
 224         return obj.__self__
 225
 226
 227 def get_meth_class(obj):
 228     """Return method class"""
 229     if PY2:
 230         # Python 2
 231         return obj.im_class
 232     else:
 233         # Python 3
 234         return obj.__self__.__class__
 235
 236
 237 # =============================================================================
 238 # Misc.
 239 # =============================================================================
 240 if PY2:
 241     # Python 2
 242     input = raw_input
 243     getcwd = os.getcwdu
 244     cmp = cmp
 245     import string
 246     str_lower = string.lower
 247     from itertools import izip_longest as zip_longest
 248 else:
 249     # Python 3
 250     input = input
 251     getcwd = os.getcwd
 252
 253     def cmp(a, b):
 254         return (a > b) - (a < b)
 255     str_lower = str.lower
 256     from itertools import zip_longest
 257
 258
 259 def qbytearray_to_str(qba):
 260     """Convert QByteArray object to str in a way compatible with Python 2/3"""
 261     return str(bytes(qba.toHex().data()).decode())