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     from collections import Callable, MutableMapping
  50     import ConfigParser as configparser
  51     try:
  52         import _winreg as winreg
  53     except ImportError:
  54         pass
  55     from sys import maxint as maxsize
  56     try:
  57         import CStringIO as io
  58     except ImportError:
  59         import StringIO as io
  60     try:
  61         import cPickle as pickle
  62     except ImportError:
  63         import pickle
  64     from UserDict import DictMixin as MutableMapping
  65     import thread as _thread
  66     import repr as reprlib
  67 else:
  68     # Python 3
  69     import builtins
  70     import configparser
  71     try:
  72         import winreg
  73     except ImportError:
  74         pass
  75     from sys import maxsize
  76     import io
  77     import pickle
  78     if PY33:
  79         from collections.abc import Callable, MutableMapping
  80     else:
  81         from collections import Callable, MutableMapping
  82     import _thread
  83     import reprlib
  84
  85
  86 # =============================================================================
  87 # Strings
  88 # =============================================================================
  89 if PY2:
  90     # Python 2
  91     import codecs
  92
  93     def u(obj):
  94         """Make unicode object"""
  95         return codecs.unicode_escape_decode(obj)[0]
  96 else:
  97     # Python 3
  98     def u(obj):
  99         """Return string as it is"""
 100         return obj
 101
 102
 103 def is_text_string(obj):
 104     """Return True if `obj` is a text string, False if it is anything else,
 105     like binary data (Python 3) or QString (Python 2, PyQt API #1)"""
 106     if PY2:
 107         # Python 2
 108         return isinstance(obj, basestring)
 109     else:
 110         # Python 3
 111         return isinstance(obj, str)
 112
 113
 114 def is_binary_string(obj):
 115     """Return True if `obj` is a binary string, False if it is anything else"""
 116     if PY2:
 117         # Python 2
 118         return isinstance(obj, str)
 119     else:
 120         # Python 3
 121         return isinstance(obj, bytes)
 122
 123
 124 def is_string(obj):
 125     """Return True if `obj` is a text or binary Python string object,
 126     False if it is anything else, like a QString (Python 2, PyQt API #1)"""
 127     return is_text_string(obj) or is_binary_string(obj)
 128
 129
 130 def is_unicode(obj):
 131     """Return True if `obj` is unicode"""
 132     if PY2:
 133         # Python 2
 134         return isinstance(obj, unicode)
 135     else:
 136         # Python 3
 137         return isinstance(obj, str)
 138
 139
 140 def to_text_string(obj, encoding=None):
 141     """Convert `obj` to (unicode) text string"""
 142     if PY2:
 143         # Python 2
 144         if encoding is None:
 145             return unicode(obj)
 146         else:
 147             return unicode(obj, encoding)
 148     else:
 149         # Python 3
 150         if encoding is None:
 151             return str(obj)
 152         elif isinstance(obj, str):
 153             # In case this function is not used properly, this could happen
 154             return obj
 155         else:
 156             return str(obj, encoding)
 157
 158
 159 def to_binary_string(obj, encoding=None):
 160     """Convert `obj` to binary string (bytes in Python 3, str in Python 2)"""
 161     if PY2:
 162         # Python 2
 163         if encoding is None:
 164             return str(obj)
 165         else:
 166             return obj.encode(encoding)
 167     else:
 168         # Python 3
 169         return bytes(obj, 'utf-8' if encoding is None else encoding)
 170
 171
 172 # =============================================================================
 173 # Function attributes
 174 # =============================================================================
 175 def get_func_code(func):
 176     """Return function code object"""
 177     if PY2:
 178         # Python 2
 179         return func.func_code
 180     else:
 181         # Python 3
 182         return func.__code__
 183
 184
 185 def get_func_name(func):
 186     """Return function name"""
 187     if PY2:
 188         # Python 2
 189         return func.func_name
 190     else:
 191         # Python 3
 192         return func.__name__
 193
 194
 195 def get_func_defaults(func):
 196     """Return function default argument values"""
 197     if PY2:
 198         # Python 2
 199         return func.func_defaults
 200     else:
 201         # Python 3
 202         return func.__defaults__
 203
 204
 205 # =============================================================================
 206 # Special method attributes
 207 # =============================================================================
 208 def get_meth_func(obj):
 209     """Return method function object"""
 210     if PY2:
 211         # Python 2
 212         return obj.im_func
 213     else:
 214         # Python 3
 215         return obj.__func__
 216
 217
 218 def get_meth_class_inst(obj):
 219     """Return method class instance"""
 220     if PY2:
 221         # Python 2
 222         return obj.im_self
 223     else:
 224         # Python 3
 225         return obj.__self__
 226
 227
 228 def get_meth_class(obj):
 229     """Return method class"""
 230     if PY2:
 231         # Python 2
 232         return obj.im_class
 233     else:
 234         # Python 3
 235         return obj.__self__.__class__
 236
 237
 238 # =============================================================================
 239 # Misc.
 240 # =============================================================================
 241 if PY2:
 242     # Python 2
 243     input = raw_input
 244     getcwd = os.getcwdu
 245     cmp = cmp
 246     import string
 247     str_lower = string.lower
 248     from itertools import izip_longest as zip_longest
 249 else:
 250     # Python 3
 251     input = input
 252     getcwd = os.getcwd
 253
 254     def cmp(a, b):
 255         return (a > b) - (a < b)
 256     str_lower = str.lower
 257     from itertools import zip_longest
 258
 259
 260 def qbytearray_to_str(qba):
 261     """Convert QByteArray object to str in a way compatible with Python 2/3"""
 262     return str(bytes(qba.toHex().data()).decode())