Restoring authorship annotation for <shadchin@yandex-team.ru>. Commit 1 of 2.

1 files changed, 401 insertions, 401 deletions

diff --git a/contrib/python/ipython/py3/IPython/external/qt_loaders.py b/contrib/python/ipython/py3/IPython/external/qt_loaders.py
index 79805358e7..ee42ca6ffb 100644
--- a/contrib/python/ipython/py3/IPython/external/qt_loaders.py
+++ b/contrib/python/ipython/py3/IPython/external/qt_loaders.py
@@ -1,401 +1,401 @@
-"""
-This module contains factory functions that attempt
-to return Qt submodules from the various python Qt bindings.
-
-It also protects against double-importing Qt with different
-bindings, which is unstable and likely to crash
-
-This is used primarily by qt and qt_for_kernel, and shouldn't
-be accessed directly from the outside
-"""
-import sys
-import types
-from functools import partial, lru_cache
-import operator
-
-from IPython.utils.version import check_version
-
-# ### Available APIs.
-# Qt6
-QT_API_PYQT6 = "pyqt6"
-QT_API_PYSIDE6 = "pyside6"
-
-# Qt5
-QT_API_PYQT5 = 'pyqt5'
-QT_API_PYSIDE2 = 'pyside2'
-
-# Qt4
-QT_API_PYQT = "pyqt"  # Force version 2
-QT_API_PYQTv1 = "pyqtv1"  # Force version 2
-QT_API_PYSIDE = "pyside"
-
-QT_API_PYQT_DEFAULT = "pyqtdefault"  # use system default for version 1 vs. 2
-
-api_to_module = {
-    # Qt6
-    QT_API_PYQT6: "PyQt6",
-    QT_API_PYSIDE6: "PySide6",
-    # Qt5
-    QT_API_PYQT5: "PyQt5",
-    QT_API_PYSIDE2: "PySide2",
-    # Qt4
-    QT_API_PYSIDE: "PySide",
-    QT_API_PYQT: "PyQt4",
-    QT_API_PYQTv1: "PyQt4",
-    # default
-    QT_API_PYQT_DEFAULT: "PyQt6",
-}
-
-
-class ImportDenier(object):
-    """Import Hook that will guard against bad Qt imports
-    once IPython commits to a specific binding
-    """
-
-    def __init__(self):
-        self.__forbidden = set()
-
-    def forbid(self, module_name):
-        sys.modules.pop(module_name, None)
-        self.__forbidden.add(module_name)
-
-    def find_module(self, fullname, path=None):
-        if path:
-            return
-        if fullname in self.__forbidden:
-            return self
-
-    def load_module(self, fullname):
-        raise ImportError("""
-    Importing %s disabled by IPython, which has
-    already imported an Incompatible QT Binding: %s
-    """ % (fullname, loaded_api()))
-
-
-ID = ImportDenier()
-sys.meta_path.insert(0, ID)
-
-
-def commit_api(api):
-    """Commit to a particular API, and trigger ImportErrors on subsequent
-       dangerous imports"""
-    modules = set(api_to_module.values())
-
-    modules.remove(api_to_module[api])
-    for mod in modules:
-        ID.forbid(mod)
-
-
-def loaded_api():
-    """Return which API is loaded, if any
-
-    If this returns anything besides None,
-    importing any other Qt binding is unsafe.
-
-    Returns
-    -------
-    None, 'pyside6', 'pyqt6', 'pyside2', 'pyside', 'pyqt', 'pyqt5', 'pyqtv1'
-    """
-    if sys.modules.get("PyQt6.QtCore"):
-        return QT_API_PYQT6
-    elif sys.modules.get("PySide6.QtCore"):
-        return QT_API_PYSIDE6
-    elif sys.modules.get("PyQt5.QtCore"):
-        return QT_API_PYQT5
-    elif sys.modules.get("PySide2.QtCore"):
-        return QT_API_PYSIDE2
-    elif sys.modules.get("PyQt4.QtCore"):
-        if qtapi_version() == 2:
-            return QT_API_PYQT
-        else:
-            return QT_API_PYQTv1
-    elif sys.modules.get("PySide.QtCore"):
-        return QT_API_PYSIDE
-
-    return None
-
-
-def has_binding(api):
-    """Safely check for PyQt4/5, PySide or PySide2, without importing submodules
-
-        Parameters
-        ----------
-        api : str [ 'pyqtv1' | 'pyqt' | 'pyqt5' | 'pyside' | 'pyside2' | 'pyqtdefault']
-             Which module to check for
-
-        Returns
-        -------
-        True if the relevant module appears to be importable
-     """
-    module_name = api_to_module[api]
-    from importlib.util import find_spec
-
-    required = ['QtCore', 'QtGui', 'QtSvg']
-    if api in (QT_API_PYQT5, QT_API_PYSIDE2, QT_API_PYQT6, QT_API_PYSIDE6):
-        # QT5 requires QtWidgets too
-        required.append('QtWidgets')
-
-    for submod in required:
-        try:
-            spec = find_spec('%s.%s' % (module_name, submod))
-        except ImportError:
-            # Package (e.g. PyQt5) not found
-            return False
-        else:
-            if spec is None:
-                # Submodule (e.g. PyQt5.QtCore) not found
-                return False
-
-    if api == QT_API_PYSIDE:
-        # We can also safely check PySide version
-        import PySide
-        return check_version(PySide.__version__, '1.0.3')
-
-    return True
-
-
-def qtapi_version():
-    """Return which QString API has been set, if any
-
-    Returns
-    -------
-    The QString API version (1 or 2), or None if not set
-    """
-    try:
-        import sip
-    except ImportError:
-        # as of PyQt5 5.11, sip is no longer available as a top-level
-        # module and needs to be imported from the PyQt5 namespace
-        try:
-            from PyQt5 import sip
-        except ImportError:
-            return
-    try:
-        return sip.getapi('QString')
-    except ValueError:
-        return
-
-
-def can_import(api):
-    """Safely query whether an API is importable, without importing it"""
-    if not has_binding(api):
-        return False
-
-    current = loaded_api()
-    if api == QT_API_PYQT_DEFAULT:
-        return current in [QT_API_PYQT6, None]
-    else:
-        return current in [api, None]
-
-
-def import_pyqt4(version=2):
-    """
-    Import PyQt4
-
-    Parameters
-    ----------
-    version : 1, 2, or None
-      Which QString/QVariant API to use. Set to None to use the system
-      default
-
-    ImportErrors rasied within this function are non-recoverable
-    """
-    # The new-style string API (version=2) automatically
-    # converts QStrings to Unicode Python strings. Also, automatically unpacks
-    # QVariants to their underlying objects.
-    import sip
-
-    if version is not None:
-        sip.setapi('QString', version)
-        sip.setapi('QVariant', version)
-
-    from PyQt4 import QtGui, QtCore, QtSvg
-
-    if not check_version(QtCore.PYQT_VERSION_STR, '4.7'):
-        raise ImportError("IPython requires PyQt4 >= 4.7, found %s" %
-                          QtCore.PYQT_VERSION_STR)
-
-    # Alias PyQt-specific functions for PySide compatibility.
-    QtCore.Signal = QtCore.pyqtSignal
-    QtCore.Slot = QtCore.pyqtSlot
-
-    # query for the API version (in case version == None)
-    version = sip.getapi('QString')
-    api = QT_API_PYQTv1 if version == 1 else QT_API_PYQT
-    return QtCore, QtGui, QtSvg, api
-
-
-def import_pyqt5():
-    """
-    Import PyQt5
-
-    ImportErrors rasied within this function are non-recoverable
-    """
-
-    from PyQt5 import QtCore, QtSvg, QtWidgets, QtGui
-
-    # Alias PyQt-specific functions for PySide compatibility.
-    QtCore.Signal = QtCore.pyqtSignal
-    QtCore.Slot = QtCore.pyqtSlot
-
-    # Join QtGui and QtWidgets for Qt4 compatibility.
-    QtGuiCompat = types.ModuleType('QtGuiCompat')
-    QtGuiCompat.__dict__.update(QtGui.__dict__)
-    QtGuiCompat.__dict__.update(QtWidgets.__dict__)
-
-    api = QT_API_PYQT5
-    return QtCore, QtGuiCompat, QtSvg, api
-
-
-def import_pyqt6():
-    """
-    Import PyQt6
-
-    ImportErrors rasied within this function are non-recoverable
-    """
-
-    from PyQt6 import QtCore, QtSvg, QtWidgets, QtGui
-
-    # Alias PyQt-specific functions for PySide compatibility.
-    QtCore.Signal = QtCore.pyqtSignal
-    QtCore.Slot = QtCore.pyqtSlot
-
-    # Join QtGui and QtWidgets for Qt4 compatibility.
-    QtGuiCompat = types.ModuleType("QtGuiCompat")
-    QtGuiCompat.__dict__.update(QtGui.__dict__)
-    QtGuiCompat.__dict__.update(QtWidgets.__dict__)
-
-    api = QT_API_PYQT6
-    return QtCore, QtGuiCompat, QtSvg, api
-
-
-def import_pyside():
-    """
-    Import PySide
-
-    ImportErrors raised within this function are non-recoverable
-    """
-    from PySide import QtGui, QtCore, QtSvg
-    return QtCore, QtGui, QtSvg, QT_API_PYSIDE
-
-def import_pyside2():
-    """
-    Import PySide2
-
-    ImportErrors raised within this function are non-recoverable
-    """
-    from PySide2 import QtGui, QtCore, QtSvg, QtWidgets, QtPrintSupport
-
-    # Join QtGui and QtWidgets for Qt4 compatibility.
-    QtGuiCompat = types.ModuleType('QtGuiCompat')
-    QtGuiCompat.__dict__.update(QtGui.__dict__)
-    QtGuiCompat.__dict__.update(QtWidgets.__dict__)
-    QtGuiCompat.__dict__.update(QtPrintSupport.__dict__)
-
-    return QtCore, QtGuiCompat, QtSvg, QT_API_PYSIDE2
-
-
-def import_pyside6():
-    """
-    Import PySide6
-
-    ImportErrors raised within this function are non-recoverable
-    """
-    from PySide6 import QtGui, QtCore, QtSvg, QtWidgets, QtPrintSupport
-
-    # Join QtGui and QtWidgets for Qt4 compatibility.
-    QtGuiCompat = types.ModuleType("QtGuiCompat")
-    QtGuiCompat.__dict__.update(QtGui.__dict__)
-    QtGuiCompat.__dict__.update(QtWidgets.__dict__)
-    QtGuiCompat.__dict__.update(QtPrintSupport.__dict__)
-
-    return QtCore, QtGuiCompat, QtSvg, QT_API_PYSIDE6
-
-
-def load_qt(api_options):
-    """
-    Attempt to import Qt, given a preference list
-    of permissible bindings
-
-    It is safe to call this function multiple times.
-
-    Parameters
-    ----------
-    api_options: List of strings
-        The order of APIs to try. Valid items are 'pyside', 'pyside2',
-        'pyqt', 'pyqt5', 'pyqtv1' and 'pyqtdefault'
-
-    Returns
-    -------
-
-    A tuple of QtCore, QtGui, QtSvg, QT_API
-    The first three are the Qt modules. The last is the
-    string indicating which module was loaded.
-
-    Raises
-    ------
-    ImportError, if it isn't possible to import any requested
-    bindings (either because they aren't installed, or because
-    an incompatible library has already been installed)
-    """
-    loaders = {
-        # Qt6
-        QT_API_PYQT6: import_pyqt6,
-        QT_API_PYSIDE6: import_pyside6,
-        # Qt5
-        QT_API_PYQT5: import_pyqt5,
-        QT_API_PYSIDE2: import_pyside2,
-        # Qt4
-        QT_API_PYSIDE: import_pyside,
-        QT_API_PYQT: import_pyqt4,
-        QT_API_PYQTv1: partial(import_pyqt4, version=1),
-        # default
-        QT_API_PYQT_DEFAULT: import_pyqt6,
-    }
-
-    for api in api_options:
-
-        if api not in loaders:
-            raise RuntimeError(
-                "Invalid Qt API %r, valid values are: %s" %
-                (api, ", ".join(["%r" % k for k in loaders.keys()])))
-
-        if not can_import(api):
-            continue
-
-        #cannot safely recover from an ImportError during this
-        result = loaders[api]()
-        api = result[-1]  # changed if api = QT_API_PYQT_DEFAULT
-        commit_api(api)
-        return result
-    else:
-        raise ImportError("""
-    Could not load requested Qt binding. Please ensure that
-    PyQt4 >= 4.7, PyQt5, PySide >= 1.0.3 or PySide2 is available,
-    and only one is imported per session.
-
-    Currently-imported Qt library:                              %r
-    PyQt4 available (requires QtCore, QtGui, QtSvg):            %s
-    PyQt5 available (requires QtCore, QtGui, QtSvg, QtWidgets): %s
-    PySide >= 1.0.3 installed:                                  %s
-    PySide2 installed:                                          %s
-    Tried to load:                                              %r
-    """ % (loaded_api(),
-           has_binding(QT_API_PYQT),
-           has_binding(QT_API_PYQT5),
-           has_binding(QT_API_PYSIDE),
-           has_binding(QT_API_PYSIDE2),
-           api_options))
-
-
-def enum_factory(QT_API, QtCore):
-    """Construct an enum helper to account for PyQt5 <-> PyQt6 changes."""
-
-    @lru_cache(None)
-    def _enum(name):
-        # foo.bar.Enum.Entry (PyQt6) <=> foo.bar.Entry (non-PyQt6).
-        return operator.attrgetter(
-            name if QT_API == QT_API_PYQT6 else name.rpartition(".")[0]
-        )(sys.modules[QtCore.__package__])
-
-    return _enum
+""" 
+This module contains factory functions that attempt 
+to return Qt submodules from the various python Qt bindings. 
+ 
+It also protects against double-importing Qt with different 
+bindings, which is unstable and likely to crash 
+ 
+This is used primarily by qt and qt_for_kernel, and shouldn't 
+be accessed directly from the outside 
+""" 
+import sys 
+import types 
+from functools import partial, lru_cache 
+import operator 
+ 
+from IPython.utils.version import check_version 
+ 
+# ### Available APIs. 
+# Qt6 
+QT_API_PYQT6 = "pyqt6" 
+QT_API_PYSIDE6 = "pyside6" 
+ 
+# Qt5 
+QT_API_PYQT5 = 'pyqt5' 
+QT_API_PYSIDE2 = 'pyside2' 
+ 
+# Qt4 
+QT_API_PYQT = "pyqt"  # Force version 2 
+QT_API_PYQTv1 = "pyqtv1"  # Force version 2 
+QT_API_PYSIDE = "pyside" 
+ 
+QT_API_PYQT_DEFAULT = "pyqtdefault"  # use system default for version 1 vs. 2 
+ 
+api_to_module = { 
+    # Qt6 
+    QT_API_PYQT6: "PyQt6", 
+    QT_API_PYSIDE6: "PySide6", 
+    # Qt5 
+    QT_API_PYQT5: "PyQt5", 
+    QT_API_PYSIDE2: "PySide2", 
+    # Qt4 
+    QT_API_PYSIDE: "PySide", 
+    QT_API_PYQT: "PyQt4", 
+    QT_API_PYQTv1: "PyQt4", 
+    # default 
+    QT_API_PYQT_DEFAULT: "PyQt6", 
+} 
+ 
+ 
+class ImportDenier(object): 
+    """Import Hook that will guard against bad Qt imports 
+    once IPython commits to a specific binding 
+    """ 
+ 
+    def __init__(self): 
+        self.__forbidden = set() 
+ 
+    def forbid(self, module_name): 
+        sys.modules.pop(module_name, None) 
+        self.__forbidden.add(module_name) 
+ 
+    def find_module(self, fullname, path=None): 
+        if path: 
+            return 
+        if fullname in self.__forbidden: 
+            return self 
+ 
+    def load_module(self, fullname): 
+        raise ImportError(""" 
+    Importing %s disabled by IPython, which has 
+    already imported an Incompatible QT Binding: %s 
+    """ % (fullname, loaded_api())) 
+ 
+ 
+ID = ImportDenier() 
+sys.meta_path.insert(0, ID) 
+ 
+ 
+def commit_api(api): 
+    """Commit to a particular API, and trigger ImportErrors on subsequent 
+       dangerous imports""" 
+    modules = set(api_to_module.values()) 
+ 
+    modules.remove(api_to_module[api]) 
+    for mod in modules: 
+        ID.forbid(mod) 
+ 
+ 
+def loaded_api(): 
+    """Return which API is loaded, if any 
+ 
+    If this returns anything besides None, 
+    importing any other Qt binding is unsafe. 
+ 
+    Returns 
+    ------- 
+    None, 'pyside6', 'pyqt6', 'pyside2', 'pyside', 'pyqt', 'pyqt5', 'pyqtv1' 
+    """ 
+    if sys.modules.get("PyQt6.QtCore"): 
+        return QT_API_PYQT6 
+    elif sys.modules.get("PySide6.QtCore"): 
+        return QT_API_PYSIDE6 
+    elif sys.modules.get("PyQt5.QtCore"): 
+        return QT_API_PYQT5 
+    elif sys.modules.get("PySide2.QtCore"): 
+        return QT_API_PYSIDE2 
+    elif sys.modules.get("PyQt4.QtCore"): 
+        if qtapi_version() == 2: 
+            return QT_API_PYQT 
+        else: 
+            return QT_API_PYQTv1 
+    elif sys.modules.get("PySide.QtCore"): 
+        return QT_API_PYSIDE 
+ 
+    return None 
+ 
+ 
+def has_binding(api): 
+    """Safely check for PyQt4/5, PySide or PySide2, without importing submodules 
+ 
+        Parameters 
+        ---------- 
+        api : str [ 'pyqtv1' | 'pyqt' | 'pyqt5' | 'pyside' | 'pyside2' | 'pyqtdefault'] 
+             Which module to check for 
+ 
+        Returns 
+        ------- 
+        True if the relevant module appears to be importable 
+     """ 
+    module_name = api_to_module[api] 
+    from importlib.util import find_spec 
+ 
+    required = ['QtCore', 'QtGui', 'QtSvg'] 
+    if api in (QT_API_PYQT5, QT_API_PYSIDE2, QT_API_PYQT6, QT_API_PYSIDE6): 
+        # QT5 requires QtWidgets too 
+        required.append('QtWidgets') 
+ 
+    for submod in required: 
+        try: 
+            spec = find_spec('%s.%s' % (module_name, submod)) 
+        except ImportError: 
+            # Package (e.g. PyQt5) not found 
+            return False 
+        else: 
+            if spec is None: 
+                # Submodule (e.g. PyQt5.QtCore) not found 
+                return False 
+ 
+    if api == QT_API_PYSIDE: 
+        # We can also safely check PySide version 
+        import PySide 
+        return check_version(PySide.__version__, '1.0.3') 
+ 
+    return True 
+ 
+ 
+def qtapi_version(): 
+    """Return which QString API has been set, if any 
+ 
+    Returns 
+    ------- 
+    The QString API version (1 or 2), or None if not set 
+    """ 
+    try: 
+        import sip 
+    except ImportError: 
+        # as of PyQt5 5.11, sip is no longer available as a top-level 
+        # module and needs to be imported from the PyQt5 namespace 
+        try: 
+            from PyQt5 import sip 
+        except ImportError: 
+            return 
+    try: 
+        return sip.getapi('QString') 
+    except ValueError: 
+        return 
+ 
+ 
+def can_import(api): 
+    """Safely query whether an API is importable, without importing it""" 
+    if not has_binding(api): 
+        return False 
+ 
+    current = loaded_api() 
+    if api == QT_API_PYQT_DEFAULT: 
+        return current in [QT_API_PYQT6, None] 
+    else: 
+        return current in [api, None] 
+ 
+ 
+def import_pyqt4(version=2): 
+    """ 
+    Import PyQt4 
+ 
+    Parameters 
+    ---------- 
+    version : 1, 2, or None 
+      Which QString/QVariant API to use. Set to None to use the system 
+      default 
+ 
+    ImportErrors rasied within this function are non-recoverable 
+    """ 
+    # The new-style string API (version=2) automatically 
+    # converts QStrings to Unicode Python strings. Also, automatically unpacks 
+    # QVariants to their underlying objects. 
+    import sip 
+ 
+    if version is not None: 
+        sip.setapi('QString', version) 
+        sip.setapi('QVariant', version) 
+ 
+    from PyQt4 import QtGui, QtCore, QtSvg 
+ 
+    if not check_version(QtCore.PYQT_VERSION_STR, '4.7'): 
+        raise ImportError("IPython requires PyQt4 >= 4.7, found %s" % 
+                          QtCore.PYQT_VERSION_STR) 
+ 
+    # Alias PyQt-specific functions for PySide compatibility. 
+    QtCore.Signal = QtCore.pyqtSignal 
+    QtCore.Slot = QtCore.pyqtSlot 
+ 
+    # query for the API version (in case version == None) 
+    version = sip.getapi('QString') 
+    api = QT_API_PYQTv1 if version == 1 else QT_API_PYQT 
+    return QtCore, QtGui, QtSvg, api 
+ 
+ 
+def import_pyqt5(): 
+    """ 
+    Import PyQt5 
+ 
+    ImportErrors rasied within this function are non-recoverable 
+    """ 
+ 
+    from PyQt5 import QtCore, QtSvg, QtWidgets, QtGui 
+ 
+    # Alias PyQt-specific functions for PySide compatibility. 
+    QtCore.Signal = QtCore.pyqtSignal 
+    QtCore.Slot = QtCore.pyqtSlot 
+ 
+    # Join QtGui and QtWidgets for Qt4 compatibility. 
+    QtGuiCompat = types.ModuleType('QtGuiCompat') 
+    QtGuiCompat.__dict__.update(QtGui.__dict__) 
+    QtGuiCompat.__dict__.update(QtWidgets.__dict__) 
+ 
+    api = QT_API_PYQT5 
+    return QtCore, QtGuiCompat, QtSvg, api 
+ 
+ 
+def import_pyqt6(): 
+    """ 
+    Import PyQt6 
+ 
+    ImportErrors rasied within this function are non-recoverable 
+    """ 
+ 
+    from PyQt6 import QtCore, QtSvg, QtWidgets, QtGui 
+ 
+    # Alias PyQt-specific functions for PySide compatibility. 
+    QtCore.Signal = QtCore.pyqtSignal 
+    QtCore.Slot = QtCore.pyqtSlot 
+ 
+    # Join QtGui and QtWidgets for Qt4 compatibility. 
+    QtGuiCompat = types.ModuleType("QtGuiCompat") 
+    QtGuiCompat.__dict__.update(QtGui.__dict__) 
+    QtGuiCompat.__dict__.update(QtWidgets.__dict__) 
+ 
+    api = QT_API_PYQT6 
+    return QtCore, QtGuiCompat, QtSvg, api 
+ 
+ 
+def import_pyside(): 
+    """ 
+    Import PySide 
+ 
+    ImportErrors raised within this function are non-recoverable 
+    """ 
+    from PySide import QtGui, QtCore, QtSvg 
+    return QtCore, QtGui, QtSvg, QT_API_PYSIDE 
+ 
+def import_pyside2(): 
+    """ 
+    Import PySide2 
+ 
+    ImportErrors raised within this function are non-recoverable 
+    """ 
+    from PySide2 import QtGui, QtCore, QtSvg, QtWidgets, QtPrintSupport 
+ 
+    # Join QtGui and QtWidgets for Qt4 compatibility. 
+    QtGuiCompat = types.ModuleType('QtGuiCompat') 
+    QtGuiCompat.__dict__.update(QtGui.__dict__) 
+    QtGuiCompat.__dict__.update(QtWidgets.__dict__) 
+    QtGuiCompat.__dict__.update(QtPrintSupport.__dict__) 
+ 
+    return QtCore, QtGuiCompat, QtSvg, QT_API_PYSIDE2 
+ 
+ 
+def import_pyside6(): 
+    """ 
+    Import PySide6 
+ 
+    ImportErrors raised within this function are non-recoverable 
+    """ 
+    from PySide6 import QtGui, QtCore, QtSvg, QtWidgets, QtPrintSupport 
+ 
+    # Join QtGui and QtWidgets for Qt4 compatibility. 
+    QtGuiCompat = types.ModuleType("QtGuiCompat") 
+    QtGuiCompat.__dict__.update(QtGui.__dict__) 
+    QtGuiCompat.__dict__.update(QtWidgets.__dict__) 
+    QtGuiCompat.__dict__.update(QtPrintSupport.__dict__) 
+ 
+    return QtCore, QtGuiCompat, QtSvg, QT_API_PYSIDE6 
+ 
+ 
+def load_qt(api_options): 
+    """ 
+    Attempt to import Qt, given a preference list 
+    of permissible bindings 
+ 
+    It is safe to call this function multiple times. 
+ 
+    Parameters 
+    ---------- 
+    api_options: List of strings 
+        The order of APIs to try. Valid items are 'pyside', 'pyside2', 
+        'pyqt', 'pyqt5', 'pyqtv1' and 'pyqtdefault' 
+ 
+    Returns 
+    ------- 
+ 
+    A tuple of QtCore, QtGui, QtSvg, QT_API 
+    The first three are the Qt modules. The last is the 
+    string indicating which module was loaded. 
+ 
+    Raises 
+    ------ 
+    ImportError, if it isn't possible to import any requested 
+    bindings (either because they aren't installed, or because 
+    an incompatible library has already been installed) 
+    """ 
+    loaders = { 
+        # Qt6 
+        QT_API_PYQT6: import_pyqt6, 
+        QT_API_PYSIDE6: import_pyside6, 
+        # Qt5 
+        QT_API_PYQT5: import_pyqt5, 
+        QT_API_PYSIDE2: import_pyside2, 
+        # Qt4 
+        QT_API_PYSIDE: import_pyside, 
+        QT_API_PYQT: import_pyqt4, 
+        QT_API_PYQTv1: partial(import_pyqt4, version=1), 
+        # default 
+        QT_API_PYQT_DEFAULT: import_pyqt6, 
+    } 
+ 
+    for api in api_options: 
+ 
+        if api not in loaders: 
+            raise RuntimeError( 
+                "Invalid Qt API %r, valid values are: %s" % 
+                (api, ", ".join(["%r" % k for k in loaders.keys()]))) 
+ 
+        if not can_import(api): 
+            continue 
+ 
+        #cannot safely recover from an ImportError during this 
+        result = loaders[api]() 
+        api = result[-1]  # changed if api = QT_API_PYQT_DEFAULT 
+        commit_api(api) 
+        return result 
+    else: 
+        raise ImportError(""" 
+    Could not load requested Qt binding. Please ensure that 
+    PyQt4 >= 4.7, PyQt5, PySide >= 1.0.3 or PySide2 is available, 
+    and only one is imported per session. 
+ 
+    Currently-imported Qt library:                              %r 
+    PyQt4 available (requires QtCore, QtGui, QtSvg):            %s 
+    PyQt5 available (requires QtCore, QtGui, QtSvg, QtWidgets): %s 
+    PySide >= 1.0.3 installed:                                  %s 
+    PySide2 installed:                                          %s 
+    Tried to load:                                              %r 
+    """ % (loaded_api(), 
+           has_binding(QT_API_PYQT), 
+           has_binding(QT_API_PYQT5), 
+           has_binding(QT_API_PYSIDE), 
+           has_binding(QT_API_PYSIDE2), 
+           api_options)) 
+ 
+ 
+def enum_factory(QT_API, QtCore): 
+    """Construct an enum helper to account for PyQt5 <-> PyQt6 changes.""" 
+ 
+    @lru_cache(None) 
+    def _enum(name): 
+        # foo.bar.Enum.Entry (PyQt6) <=> foo.bar.Entry (non-PyQt6). 
+        return operator.attrgetter( 
+            name if QT_API == QT_API_PYQT6 else name.rpartition(".")[0] 
+        )(sys.modules[QtCore.__package__]) 
+ 
+    return _enum