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