qtpy/__init__.py

   1 # -*- coding: utf-8 -*-
   2 #
   3 # Copyright © 2009- The Spyder Development Team
   4 # Copyright © 2014-2015 Colin Duquesnoy
   5 #
   6 # Licensed under the terms of the MIT License
   7 # (see LICENSE.txt for details)
   8
   9 """
  10 **QtPy** is a shim over the various Python Qt bindings. It is used to write
  11 Qt binding independent libraries or applications.
  12
  13 If one of the APIs has already been imported, then it will be used.
  14
  15 Otherwise, the shim will automatically select the first available API (PyQt5,
  16 PySide2, PyQt4 and finally PySide); in that case, you can force the use of one
  17 specific bindings (e.g. if your application is using one specific bindings and
  18 you need to use library that use QtPy) by setting up the ``QT_API`` environment
  19 variable.
  20
  21 PyQt5
  22 =====
  23
  24 For PyQt5, you don't have to set anything as it will be used automatically::
  25
  26     >>> from qtpy import QtGui, QtWidgets, QtCore
  27     >>> print(QtWidgets.QWidget)
  28
  29
  30 PySide2
  31 ======
  32
  33 Set the QT_API environment variable to 'pyside2' before importing other
  34 packages::
  35
  36     >>> import os
  37     >>> os.environ['QT_API'] = 'pyside2'
  38     >>> from qtpy import QtGui, QtWidgets, QtCore
  39     >>> print(QtWidgets.QWidget)
  40
  41 PyQt4
  42 =====
  43
  44 Set the ``QT_API`` environment variable to 'pyqt' before importing any python
  45 package::
  46
  47     >>> import os
  48     >>> os.environ['QT_API'] = 'pyqt'
  49     >>> from qtpy import QtGui, QtWidgets, QtCore
  50     >>> print(QtWidgets.QWidget)
  51
  52 PySide
  53 ======
  54
  55 Set the QT_API environment variable to 'pyside' before importing other
  56 packages::
  57
  58     >>> import os
  59     >>> os.environ['QT_API'] = 'pyside'
  60     >>> from qtpy import QtGui, QtWidgets, QtCore
  61     >>> print(QtWidgets.QWidget)
  62
  63 """
  64
  65 from distutils.version import LooseVersion
  66 import os
  67 import platform
  68 import sys
  69 import warnings
  70
  71 # Version of QtPy
  72 from ._version import __version__
  73 from .py3compat import PY2
  74
  75
  76 class PythonQtError(RuntimeError):
  77     """Error raise if no bindings could be selected."""
  78     pass
  79
  80
  81 class PythonQtWarning(Warning):
  82     """Warning if some features are not implemented in a binding."""
  83     pass
  84
  85
  86 # Qt API environment variable name
  87 QT_API = 'QT_API'
  88
  89 # Names of the expected PyQt5 api
  90 PYQT5_API = ['pyqt5']
  91
  92 # Names of the expected PyQt4 api
  93 PYQT4_API = [
  94     'pyqt',  # name used in IPython.qt
  95     'pyqt4'  # pyqode.qt original name
  96 ]
  97
  98 # Names of the expected PySide api
  99 PYSIDE_API = ['pyside']
 100
 101 # Names of the expected PySide2 api
 102 PYSIDE2_API = ['pyside2']
 103
 104 # Detecting if a binding was specified by the user
 105 binding_specified = QT_API in os.environ
 106
 107 # Setting a default value for QT_API
 108 os.environ.setdefault(QT_API, 'pyqt5')
 109
 110 API = os.environ[QT_API].lower()
 111 initial_api = API
 112 assert API in (PYQT5_API + PYQT4_API + PYSIDE_API + PYSIDE2_API)
 113
 114 is_old_pyqt = is_pyqt46 = False
 115 PYQT5 = True
 116 PYQT4 = PYSIDE = PYSIDE2 = False
 117
 118 # When `FORCE_QT_API` is set, we disregard
 119 # any previously imported python bindings.
 120 if not os.environ.get('FORCE_QT_API'):
 121     if 'PyQt5' in sys.modules:
 122         API = initial_api if initial_api in PYQT5_API else 'pyqt5'
 123     elif 'PySide2' in sys.modules:
 124         API = initial_api if initial_api in PYSIDE2_API else 'pyside2'
 125     elif 'PyQt4' in sys.modules:
 126         API = initial_api if initial_api in PYQT4_API else 'pyqt4'
 127     elif 'PySide' in sys.modules:
 128         API = initial_api if initial_api in PYSIDE_API else 'pyside'
 129
 130
 131 if API in PYQT5_API:
 132     try:
 133         from PyQt5.QtCore import PYQT_VERSION_STR as PYQT_VERSION  # analysis:ignore
 134         from PyQt5.QtCore import QT_VERSION_STR as QT_VERSION  # analysis:ignore
 135         PYSIDE_VERSION = None
 136
 137         if sys.platform == 'darwin':
 138             macos_version = LooseVersion(platform.mac_ver()[0])
 139             if macos_version < LooseVersion('10.10'):
 140                 if LooseVersion(QT_VERSION) >= LooseVersion('5.9'):
 141                     raise PythonQtError("Qt 5.9 or higher only works in "
 142                                         "macOS 10.10 or higher. Your "
 143                                         "program will fail in this "
 144                                         "system.")
 145             elif macos_version < LooseVersion('10.11'):
 146                 if LooseVersion(QT_VERSION) >= LooseVersion('5.11'):
 147                     raise PythonQtError("Qt 5.11 or higher only works in "
 148                                         "macOS 10.11 or higher. Your "
 149                                         "program will fail in this "
 150                                         "system.")
 151
 152             del macos_version
 153     except ImportError:
 154         API = os.environ['QT_API'] = 'pyside2'
 155
 156 if API in PYSIDE2_API:
 157     try:
 158         from PySide2 import __version__ as PYSIDE_VERSION  # analysis:ignore
 159         from PySide2.QtCore import __version__ as QT_VERSION  # analysis:ignore
 160
 161         PYQT_VERSION = None
 162         PYQT5 = False
 163         PYSIDE2 = True
 164
 165         if sys.platform == 'darwin':
 166             macos_version = LooseVersion(platform.mac_ver()[0])
 167             if macos_version < LooseVersion('10.11'):
 168                 if LooseVersion(QT_VERSION) >= LooseVersion('5.11'):
 169                     raise PythonQtError("Qt 5.11 or higher only works in "
 170                                         "macOS 10.11 or higher. Your "
 171                                         "program will fail in this "
 172                                         "system.")
 173
 174             del macos_version
 175     except ImportError:
 176         API = os.environ['QT_API'] = 'pyqt'
 177
 178 if API in PYQT4_API:
 179     try:
 180         import sip
 181         try:
 182             sip.setapi('QString', 2)
 183             sip.setapi('QVariant', 2)
 184             sip.setapi('QDate', 2)
 185             sip.setapi('QDateTime', 2)
 186             sip.setapi('QTextStream', 2)
 187             sip.setapi('QTime', 2)
 188             sip.setapi('QUrl', 2)
 189         except (AttributeError, ValueError):
 190             # PyQt < v4.6
 191             pass
 192         try:
 193             from PyQt4.Qt import PYQT_VERSION_STR as PYQT_VERSION  # analysis:ignore
 194             from PyQt4.Qt import QT_VERSION_STR as QT_VERSION  # analysis:ignore
 195         except ImportError:
 196             # In PyQt4-sip 4.19.13 PYQT_VERSION_STR and QT_VERSION_STR are in PyQt4.QtCore
 197             from PyQt4.QtCore import PYQT_VERSION_STR as PYQT_VERSION  # analysis:ignore
 198             from PyQt4.QtCore import QT_VERSION_STR as QT_VERSION  # analysis:ignore
 199         PYSIDE_VERSION = None
 200         PYQT5 = False
 201         PYQT4 = True
 202     except ImportError:
 203         API = os.environ['QT_API'] = 'pyside'
 204     else:
 205         is_old_pyqt = PYQT_VERSION.startswith(('4.4', '4.5', '4.6', '4.7'))
 206         is_pyqt46 = PYQT_VERSION.startswith('4.6')
 207
 208 if API in PYSIDE_API:
 209     try:
 210         from PySide import __version__ as PYSIDE_VERSION  # analysis:ignore
 211         from PySide.QtCore import __version__ as QT_VERSION  # analysis:ignore
 212         PYQT_VERSION = None
 213         PYQT5 = PYSIDE2 = False
 214         PYSIDE = True
 215     except ImportError:
 216         raise PythonQtError('No Qt bindings could be found')
 217
 218 # If a correct API name is passed to QT_API and it could not be found,
 219 # switches to another and informs through the warning
 220 if API != initial_api and binding_specified:
 221     warnings.warn('Selected binding "{}" could not be found, '
 222                   'using "{}"'.format(initial_api, API), RuntimeWarning)
 223
 224 API_NAME = {'pyqt5': 'PyQt5', 'pyqt': 'PyQt4', 'pyqt4': 'PyQt4',
 225             'pyside': 'PySide', 'pyside2':'PySide2'}[API]
 226
 227 if PYQT4:
 228     import sip
 229     try:
 230         API_NAME += (" (API v{0})".format(sip.getapi('QString')))
 231     except AttributeError:
 232         pass
 233
 234 try:
 235     # QtDataVisualization backward compatibility (QtDataVisualization vs. QtDatavisualization)
 236     # Only available for Qt5 bindings > 5.9 on Windows
 237     from . import QtDataVisualization as QtDatavisualization
 238 except ImportError:
 239     pass