Improving uno.py code style

* Fixing pep8 violations
* Improving comments, docstrings, and unifying coding style
* Using functionality copied from six library for Python 2/3 compatibility
* Using standard traceback formatting

Change-Id: I62bd0e8513ffc59202163002fa4adea3d92572c3
Reviewed-on: https://gerrit.libreoffice.org/22848
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Stahl <mstahl@redhat.com>
Tested-by: Michael Stahl <mstahl@redhat.com>

pyuno/source/module/uno.py

@@ -16,208 +16,278 @@
 #   except in compliance with the License. You may obtain a copy of
 #   the License at http://www.apache.org/licenses/LICENSE-2.0 .
 #
-import sys
-
 import pyuno
+import sys
+import traceback
+import warnings
 
-try:
+# since on Windows sal3.dll no longer calls WSAStartup
-    import __builtin__
+import socket
-except ImportError:
-    import builtins as __builtin__
 
-try:
+# Some Python 2/3 compatibility code copied from the six library
-    unicode
+PY2 = sys.version_info[0] == 2
-except NameError:
-    # Python 3 compatibility
-    unicode = str
 
-import socket # since on Windows sal3.dll no longer calls WSAStartup
+if PY2:
+    six_string_types = basestring,
+else:
+    six_string_types = str,
+
+# All functions and variables starting with a underscore (_) must be
+# considered private and can be changed at any time. Don't use them.
+_component_context = pyuno.getComponentContext()
 
-# all functions and variables starting with a underscore (_) must be considered private
-# and can be changed at any time. Don't use them
-_g_ctx = pyuno.getComponentContext( )
-_g_delegatee = __builtin__.__dict__["__import__"]
 
 def getComponentContext():
-    """ returns the UNO component context, that was used to initialize the python runtime.
+    """Returns the UNO component context used to initialize the Python runtime."""
+
+    return _component_context
+
+
+def getCurrentContext():
+    """Returns the current context.
+
+    See http://udk.openoffice.org/common/man/concept/uno_contexts.html#current_context
+    for an explanation on the current context concept.
     """
-    return _g_ctx
 
-def getConstantByName( constant ):
+    return pyuno.getCurrentContext()
-    "Looks up the value of a idl constant by giving its explicit name"
-    return pyuno.getConstantByName( constant )
 
-def getTypeByName( typeName):
+
-    """ returns a uno.Type instance of the type given by typeName. In case the
+def setCurrentContext(newContext):
-        type does not exist, a com.sun.star.uno.RuntimeException is raised.
+    """Sets newContext as new UNO context.
+
+    The newContext must implement the XCurrentContext interface. The
+    implementation should handle the desired properties and delegate
+    unknown properties to the old context. Ensure that the old one
+    is reset when you leave your stack, see
+    http://udk.openoffice.org/common/man/concept/uno_contexts.html#current_context
     """
-    return pyuno.getTypeByName( typeName )
 
-def createUnoStruct( typeName, *args, **kwargs ):
+    return pyuno.setCurrentContext(newContext)
-    """creates a uno struct or exception given by typeName. Can be called with:
+
+
+def getConstantByName(constant):
+    """Looks up the value of an IDL constant by giving its explicit name."""
+
+    return pyuno.getConstantByName(constant)
+
+
+def getTypeByName(typeName):
+    """Returns a `uno.Type` instance of the type given by typeName.
+
+    If the type does not exist, a `com.sun.star.uno.RuntimeException` is raised.
+    """
+
+    return pyuno.getTypeByName(typeName)
+
+
+def createUnoStruct(typeName, *args, **kwargs):
+    """Creates a UNO struct or exception given by typeName.
+
+    Can be called with:
+
     1) No additional argument.
-       In this case, you get a default constructed uno structure.
+       In this case, you get a default constructed UNO structure.
-       ( e.g. createUnoStruct( "com.sun.star.uno.Exception" ) )
+       (e.g. `createUnoStruct("com.sun.star.uno.Exception")`)
     2) Exactly one additional argument that is an instance of typeName.
        In this case, a copy constructed instance of typeName is returned
-       ( e.g. createUnoStruct( "com.sun.star.uno.Exception" , e ) )
+       (e.g. `createUnoStruct("com.sun.star.uno.Exception" , e)`)
     3) As many additional arguments as the number of elements within typeName
-       (e.g. createUnoStruct( "com.sun.star.uno.Exception", "foo error" , self) ).
+       (e.g. `createUnoStruct("com.sun.star.uno.Exception", "foo error" , self)`).
     4) Keyword arguments to give values for each element of the struct by name.
     5) A mix of 3) and 4), such that each struct element is given a value exactly once,
        either by a positional argument or by a keyword argument.
+
     The additional and/or keyword arguments must match the type of each struct element,
     otherwise an exception is thrown.
     """
-    return getClass(typeName)( *args, **kwargs )
 
-def getClass( typeName ):
+    return getClass(typeName)(*args, **kwargs)
-    """returns the class of a concrete uno exception, struct or interface
+
-    """
+
+def getClass(typeName):
+    """Returns the class of a concrete UNO exception, struct, or interface."""
+
     return pyuno.getClass(typeName)
 
-def isInterface( obj ):
+
-    """returns true, when obj is a class of a uno interface"""
+def isInterface(obj):
-    return pyuno.isInterface( obj )
+    """Returns True, when obj is a class of a UNO interface."""
+
+    return pyuno.isInterface(obj)
+
 
 def generateUuid():
-    "returns a 16 byte sequence containing a newly generated uuid or guid, see rtl/uuid.h "
+    """Returns a 16 byte sequence containing a newly generated uuid or guid.
+
+    For more information, see rtl/uuid.h.
+    """
+
     return pyuno.generateUuid()
 
-def systemPathToFileUrl( systemPath ):
-    "returns a file-url for the given system path"
-    return pyuno.systemPathToFileUrl( systemPath )
 
-def fileUrlToSystemPath( url ):
+def systemPathToFileUrl(systemPath):
-    "returns a system path (determined by the system, the python interpreter is running on)"
+    """Returns a file URL for the given system path."""
-    return pyuno.fileUrlToSystemPath( url )
 
-def absolutize( path, relativeUrl ):
+    return pyuno.systemPathToFileUrl(systemPath)
-    "returns an absolute file url from the given urls"
-    return pyuno.absolutize( path, relativeUrl )
 
-def getCurrentContext():
+
-    """Returns the currently valid current context.
+def fileUrlToSystemPath(url):
-       see http://udk.openoffice.org/common/man/concept/uno_contexts.html#current_context
+    """Returns a system path.
-       for an explanation on the current context concept
+
+    This path is determined by the system that the Python interpreter is running on.
     """
-    return pyuno.getCurrentContext()
 
-def setCurrentContext( newContext ):
+    return pyuno.fileUrlToSystemPath(url)
-    """Sets newContext as new uno current context. The newContext must
+
-    implement the XCurrentContext interface. The implementation should
+
-    handle the desired properties and delegate unknown properties to the
+def absolutize(path, relativeUrl):
-    old context. Ensure to reset the old one when you leave your stack ...
+    """Returns an absolute file url from the given urls."""
-    see http://udk.openoffice.org/common/man/concept/uno_contexts.html#current_context
+
-    """
+    return pyuno.absolutize(path, relativeUrl)
-    return pyuno.setCurrentContext( newContext )
 
 
 class Enum:
-    "Represents a UNO idl enum, use an instance of this class to explicitly pass a boolean to UNO"
+    """Represents a UNO enum.
-    #typeName the name of the enum as a string
+
-    #value    the actual value of this enum as a string
+    Use an instance of this class to explicitly pass an enum to UNO.
-    def __init__(self,typeName, value):
+
+    :param typeName: The name of the enum as a string.
+    :param value: The actual value of this enum as a string.
+    """
+
+    def __init__(self, typeName, value):
         self.typeName = typeName
         self.value = value
-        pyuno.checkEnum( self )
+        pyuno.checkEnum(self)
 
     def __repr__(self):
-        return "<uno.Enum %s (%r)>" % (self.typeName, self.value)
+        return "<Enum instance %s (%r)>" % (self.typeName, self.value)
 
     def __eq__(self, that):
         if not isinstance(that, Enum):
             return False
+
         return (self.typeName == that.typeName) and (self.value == that.value)
 
+
 class Type:
-    "Represents a UNO type, use an instance of this class to explicitly pass a boolean to UNO"
+    """Represents a UNO type.
-#    typeName                 # Name of the UNO type
+
-#    typeClass                # python Enum of TypeClass,  see com/sun/star/uno/TypeClass.idl
+    Use an instance of this class to explicitly pass a type to UNO.
+
+    :param typeName: Name of the UNO type
+    :param typeClass: Python Enum of TypeClass, see com/sun/star/uno/TypeClass.idl
+    """
+
     def __init__(self, typeName, typeClass):
         self.typeName = typeName
         self.typeClass = typeClass
         pyuno.checkType(self)
+
     def __repr__(self):
         return "<Type instance %s (%r)>" % (self.typeName, self.typeClass)
 
     def __eq__(self, that):
         if not isinstance(that, Type):
             return False
+
         return self.typeClass == that.typeClass and self.typeName == that.typeName
 
     def __hash__(self):
         return self.typeName.__hash__()
 
+
 class Bool(object):
-    """Represents a UNO boolean, use an instance of this class to explicitly
+    """Represents a UNO boolean.
-       pass a boolean to UNO.
+
-       Note: This class is deprecated. Use python's True and False directly instead
+    Use an instance of this class to explicitly pass a boolean to UNO.
+
+    Note: This class is deprecated. Use Python's True and False directly instead.
     """
+
     def __new__(cls, value):
-        if isinstance(value, (str, unicode)) and value == "true":
+        message = "The Bool class is deprecated. Use Python's True and False directly instead."
+        warnings.warn(message, DeprecationWarning)
+
+        if isinstance(value, six_string_types) and value == "true":
             return True
-        if isinstance(value, (str, unicode)) and value == "false":
+
+        if isinstance(value, six_string_types) and value == "false":
             return False
+
         if value:
             return True
+
         return False
 
+
 class Char:
-    "Represents a UNO char, use an instance of this class to explicitly pass a char to UNO"
+    """Represents a UNO char.
-    # @param value pass a Unicode string with length 1
+
-    def __init__(self,value):
+    Use an instance of this class to explicitly pass a char to UNO.
-        assert isinstance(value, unicode)
+
-        assert len(value) == 1
+    For Python 2, this class only works with unicode objects. Creating
-        self.value=value
+    a Char instance with a normal str object or comparing a Char instance
+    to a normal str object will raise an AssertionError.
+
+    :param value: A Unicode string with length 1
+    """
+
+    def __init__(self, value):
+        if PY2:
+            assert isinstance(value, unicode), "Expected unicode object, got %s instead." % type(value)
+        else:
+            assert isinstance(value, str), "Expected str object, got %s instead." % type(value)
+
+        assert len(value) == 1, "Char value must have length of 1."
+
+        self.value = value
 
     def __repr__(self):
-        return "<Char instance %s>" % (self.value, )
+        return "<Char instance %s>" % (self.value,)
 
     def __eq__(self, that):
-        if isinstance(that, (str, unicode)):
+        if isinstance(that, six_string_types):
             if len(that) > 1:
                 return False
+
             return self.value == that[0]
+
         if isinstance(that, Char):
             return self.value == that.value
+
         return False
 
-# Suggested by Christian, but still some open problems which need to be solved first
-#
-#class ByteSequence(str):
-#
-#    def __repr__(self):
-#        return "<ByteSequence instance %s>" % str.__repr__(self)
-
-    # for a little bit compatibility; setting value is not possible as
-    # strings are immutable
-#    def _get_value(self):
-#        return self
-#
-#    value = property(_get_value)
 
 class ByteSequence:
+    """Represents a UNO ByteSequence value.
+
+    Use an instance of this class to explicitly pass a byte sequence to UNO.
+
+    :param value: A string or bytesequence
+    """
+
     def __init__(self, value):
         if isinstance(value, bytes):
             self.value = value
-        elif isinstance(value, str):
+
-            self.value = value.encode("utf-8") # Python 2 compatibility
         elif isinstance(value, ByteSequence):
             self.value = value.value
+
         else:
-            raise TypeError("expected string or bytesequence")
+            raise TypeError("Expected bytes object or ByteSequence, got %s instead." % type(value))
 
     def __repr__(self):
-        return "<ByteSequence instance '%s'>" % (self.value, )
+        return "<ByteSequence instance '%s'>" % (self.value,)
 
     def __eq__(self, that):
-        if isinstance( that, ByteSequence):
-            return self.value == that.value
         if isinstance(that, bytes):
             return self.value == that
-        if isinstance(that, str):
+
-            return self.value == that.encode("utf-8")
+        if isinstance(that, ByteSequence):
+            return self.value == that.value
+
         return False
 
     def __len__(self):
@@ -226,211 +296,256 @@ class ByteSequence:
     def __getitem__(self, index):
         return self.value[index]
 
-    def __iter__( self ):
+    def __iter__(self):
         return self.value.__iter__()
 
-    def __add__( self , b ):
+    def __add__(self, b):
-        if isinstance( b, bytes):
+        if isinstance(b, bytes):
             return ByteSequence(self.value + b)
-        elif isinstance( b, str ):
-            return ByteSequence( self.value + b.encode("utf-8") )
-        elif isinstance( b, ByteSequence ):
-            return ByteSequence( self.value + b.value )
-        raise TypeError( "expected string or ByteSequence as operand" )
 
-    def __hash__( self ):
+        elif isinstance(b, ByteSequence):
+            return ByteSequence(self.value + b.value)
+
+        else:
+            raise TypeError("Can't add ByteString and %s." % type(b))
+
+    def __hash__(self):
         return self.value.hash()
 
 
 class Any:
-    "use only in connection with uno.invoke() to pass an explicit typed any"
+    """Represents a UNO Any value.
-    def __init__(self, type, value ):
+
-        if isinstance( type, Type ):
+    Use only in connection with uno.invoke() to pass an explicit typed Any.
+    """
+
+    def __init__(self, type, value):
+        if isinstance(type, Type):
             self.type = type
         else:
-            self.type = getTypeByName( type )
+            self.type = getTypeByName(type)
+
         self.value = value
 
-def invoke( object, methodname, argTuple ):
-    "use this function to pass exactly typed anys to the callee (using uno.Any)"
-    return pyuno.invoke( object, methodname, argTuple )
 
-#---------------------------------------------------------------------------------------
+def invoke(object, methodname, argTuple):
-# don't use any functions beyond this point, private section, likely to change
+    """Use this function to pass exactly typed Anys to the callee (using uno.Any)."""
-#---------------------------------------------------------------------------------------
+
-#def _uno_import( name, globals={}, locals={}, fromlist=[], level=-1 ):
+    return pyuno.invoke(object, methodname, argTuple)
-def _uno_import( name, *optargs, **kwargs ):
+
+
+# -----------------------------------------------------------------------------
+# Don't use any functions beyond this point; private section, likely to change.
+# -----------------------------------------------------------------------------
+_builtin_import = __import__
+
+
+def _uno_import(name, *optargs, **kwargs):
+    """Overrides built-in import to allow directly importing LibreOffice classes."""
+
     try:
-#       print "optargs = " + repr(optargs)
+        return _builtin_import(name, *optargs, **kwargs)
-        return _g_delegatee( name, *optargs, **kwargs )
     except ImportError as e:
         # process optargs
-        globals, locals, fromlist = list(optargs)[:3] + [kwargs.get('globals',{}), kwargs.get('locals',{}), kwargs.get('fromlist',[])][len(optargs):]
+        globals, locals, fromlist = list(optargs)[:3] + [kwargs.get('globals', {}), kwargs.get('locals', {}),
+                                                         kwargs.get('fromlist', [])][len(optargs):]
+
         # from import form only, but skip if an uno lookup has already failed
         if not fromlist or hasattr(e, '_uno_import_failed'):
             raise
+
         # hang onto exception for possible use on subsequent uno lookup failure
         py_import_exc = e
-    modnames = name.split( "." )
+
     mod = None
     d = sys.modules
-    for x in modnames:
+
-        if x in d:
+    for module in name.split("."):
-           mod = d[x]
+        if module in d:
+            mod = d[module]
         else:
-           mod = pyuno.__class__(x)  # How to create a module ??
+            # How to create a module ??
+            mod = pyuno.__class__(module)
+
         d = mod.__dict__
 
-    RuntimeException = pyuno.getClass( "com.sun.star.uno.RuntimeException" )
+    RuntimeException = pyuno.getClass("com.sun.star.uno.RuntimeException")
-    for x in fromlist:
+
-       if x not in d:
+    for class_name in fromlist:
-          failed = False
+        if class_name not in d:
-          if x.startswith( "typeOf" ):
+            failed = False
-             try:
+
-                d[x] = pyuno.getTypeByName( name + "." + x[6:len(x)] )
-             except RuntimeException:
-                failed = True
-          else:
             try:
                 # check for structs, exceptions or interfaces
-                d[x] = pyuno.getClass( name + "." + x )
+                d[class_name] = pyuno.getClass(name + "." + class_name)
             except RuntimeException:
                 # check for enums
                 try:
-                   d[x] = Enum( name , x )
+                    d[class_name] = Enum(name, class_name)
                 except RuntimeException:
-                   # check for constants
+                    # check for constants
-                   try:
+                    try:
-                      d[x] = getConstantByName( name + "." + x )
+                        d[class_name] = getConstantByName(name + "." + class_name)
-                   except RuntimeException:
+                    except RuntimeException:
-                      # check for constant group
+                        # check for constant group
-                      try:
+                        try:
-                          d[x] = _impl_getConstantGroupByName( name, x )
+                            d[class_name] = _impl_getConstantGroupByName(name, class_name)
-                      except ValueError:
+                        except ValueError:
-                          failed = True
+                            failed = True
 
-          if failed:
+            if failed:
-              # We have an import failure, but cannot distinguish between
+                # We have an import failure, but cannot distinguish between
-              # uno and non-uno errors as uno lookups are attempted for all
+                # uno and non-uno errors as uno lookups are attempted for all
-              # "from xxx import yyy" imports following a python failure.
+                # "from xxx import yyy" imports following a python failure.
-              #
+                #
-              # In Python 3, the original python exception traceback is reused
+                # In Python 3, the original python exception traceback is reused
-              # to help pinpoint the actual failing location.  Its original
+                # to help pinpoint the actual failing location.  Its original
-              # message, unlike Python 2, is unlikely to be helpful for uno
+                # message, unlike Python 2, is unlikely to be helpful for uno
-              # failures, as it most commonly is just a top level module like
+                # failures, as it most commonly is just a top level module like
-              # 'com'.  So our exception appends the uno lookup failure.
+                # 'com'.  So our exception appends the uno lookup failure.
-              # This is more ambiguous, but it plus the traceback should be
+                # This is more ambiguous, but it plus the traceback should be
-              # sufficient to identify a root cause for python or uno issues.
+                # sufficient to identify a root cause for python or uno issues.
-              #
+                #
-              # Our exception is raised outside of the nested exception
+                # Our exception is raised outside of the nested exception
-              # handlers above, to avoid Python 3 nested exception
+                # handlers above, to avoid Python 3 nested exception
-              # information for the RuntimeExceptions during lookups.
+                # information for the RuntimeExceptions during lookups.
-              #
+                #
-              # Finally, a private attribute is used to prevent further
+                # Finally, a private attribute is used to prevent further
-              # processing if this failure was in a nested import.  That
+                # processing if this failure was in a nested import.  That
-              # keeps the exception relevant to the primary failure point,
+                # keeps the exception relevant to the primary failure point,
-              # preventing us from re-processing our own import errors.
+                # preventing us from re-processing our own import errors.
 
-              uno_import_exc = ImportError("%s (or '%s.%s' is unknown)" %
+                uno_import_exc = ImportError("%s (or '%s.%s' is unknown)" %
-                                           (py_import_exc, name, x))
+                                             (py_import_exc, name, class_name))
-              if sys.version_info[0] >= 3:
+
-                  uno_import_exc = uno_import_exc.with_traceback(py_import_exc.__traceback__)
+                if sys.version_info[0] >= 3:
-              uno_import_exc._uno_import_failed = True
+                    uno_import_exc = uno_import_exc.with_traceback(py_import_exc.__traceback__)
-              raise uno_import_exc
+
+                uno_import_exc._uno_import_failed = True
+                raise uno_import_exc
 
     return mod
 
-# private
-class _ConstantGroup(object):
-    __slots__ = ['_constants']
-    def __init__(self, constants):
-        self._constants = constants
-    def __dir__(self):
-        return self._constants.keys()
-    def __getattr__(self,name):
-        if name in self._constants:
-            return self._constants[name]
-        raise AttributeError
 
-# private
+try:
-def _impl_getConstantGroupByName( module, group ):
+    import __builtin__
-    CONSTANTS = Enum('com.sun.star.uno.TypeClass', 'CONSTANTS')
+except ImportError:
-    ONE = Enum('com.sun.star.reflection.TypeDescriptionSearchDepth', 'ONE')
+    import builtins as __builtin__
-    tdm = _g_ctx.getValueByName('/singletons/com.sun.star.reflection.theTypeDescriptionManager')
-    tde = tdm.createTypeDescriptionEnumeration(module,(CONSTANTS,),ONE)
-    qualifiedName = module + '.' + group
-    for td in tde:
-        if td.Name == qualifiedName:
-            return_dict = dict()
-            for c in td.Constants:
-                return_dict.update({c.Name.split('.')[-1]: c.ConstantValue})
-            return _ConstantGroup(return_dict)
-    else:
-        raise ValueError
-
-# private function, don't use
-def _impl_extractName(name):
-    r = list(range(len(name)-1,0,-1))
-    for i in r:
-        if name[i] == ".":
-           name = name[i+1:len(name)]
-           break
-    return name
-
-# private, referenced from the pyuno shared library
-def _uno_struct__init__(self,*args, **kwargs):
-    if len(kwargs) == 0 and len(args) == 1 and hasattr(args[0], "__class__") and args[0].__class__ == self.__class__ :
-        self.__dict__["value"] = args[0]
-    else:
-        struct, used = pyuno._createUnoStructHelper(self.__class__.__pyunostruct__,args,**kwargs)
-        for kw in kwargs.keys():
-            if not (kw in used and used[kw]):
-                RuntimeException = pyuno.getClass( "com.sun.star.uno.RuntimeException" )
-                raise RuntimeException("_uno_struct__init__: unused keyword argument '" + kw + "'", None)
-        self.__dict__["value"] = struct
-
-# private, referenced from the pyuno shared library
-def _uno_struct__getattr__(self,name):
-    return __builtin__.getattr(self.__dict__["value"],name)
-
-# private, referenced from the pyuno shared library
-def _uno_struct__setattr__(self,name,value):
-    return __builtin__.setattr(self.__dict__["value"],name,value)
-
-# private, referenced from the pyuno shared library
-def _uno_struct__repr__(self):
-    return repr(self.__dict__["value"])
-
-def _uno_struct__str__(self):
-    return str(self.__dict__["value"])
-
-# private, referenced from the pyuno shared library
-def _uno_struct__eq__(self,cmp):
-    if hasattr(cmp,"value"):
-       return self.__dict__["value"] == cmp.__dict__["value"]
-    return False
-
-# referenced from pyuno shared lib and pythonscript.py
-def _uno_extract_printable_stacktrace( trace ):
-    mod = None
-    try:
-        mod = __import__("traceback")
-    except ImportError as e:
-        pass
-    ret = ""
-    if mod:
-        lst = mod.extract_tb( trace )
-        max = len(lst)
-        for j in range(max):
-            i = lst[max-j-1]
-            ret = ret + "  " + str(i[0]) + ":" + \
-                  str(i[1]) + " in function " + \
-                  str(i[2])  + "() [" + str(i[3]) + "]\n"
-    else:
-        ret = "Couldn't import traceback module"
-    return ret
 
 # hook into the __import__ chain
-__builtin__.__dict__["__import__"] = _uno_import
+__builtin__.__dict__['__import__'] = _uno_import
+
+
+class _ConstantGroup(object):
+    """Represents a group of UNOIDL constants."""
+
+    __slots__ = ['_constants']
+
+    def __init__(self, constants):
+        self._constants = constants
+
+    def __dir__(self):
+        return self._constants.keys()
+
+    def __getattr__(self, name):
+        if name in self._constants:
+            return self._constants[name]
+
+        raise AttributeError("The constant '%s' could not be found." % name)
+
+
+def _impl_getConstantGroupByName(module, group):
+    """Gets UNOIDL constant group by name."""
+
+    constants = Enum('com.sun.star.uno.TypeClass', 'CONSTANTS')
+    one = Enum('com.sun.star.reflection.TypeDescriptionSearchDepth', 'ONE')
+    type_desc_mgr = _component_context.getValueByName('/singletons/com.sun.star.reflection.theTypeDescriptionManager')
+    type_descs = type_desc_mgr.createTypeDescriptionEnumeration(module, (constants,), one)
+    qualified_name = module + '.' + group
+
+    for type_desc in type_descs:
+        if type_desc.Name == qualified_name:
+            return _ConstantGroup(dict(
+                (c.Name.split('.')[-1], c.ConstantValue)
+                for c in type_desc.Constants))
+
+    raise ValueError("The constant group '%s' could not be found." % qualified_name)
+
+
+def _uno_struct__init__(self, *args, **kwargs):
+    """Initializes a UNO struct.
+
+    Referenced from the pyuno shared library.
+
+    This function can be called with either an already constructed UNO struct, which it
+    will then just reference without copying, or with arguments to create a new UNO struct.
+    """
+
+    # Check to see if this function was passed an existing UNO struct
+    if len(kwargs) == 0 and len(args) == 1 and getattr(args[0], "__class__", None) == self.__class__:
+        self.__dict__['value'] = args[0]
+    else:
+        struct, used = pyuno._createUnoStructHelper(self.__class__.__pyunostruct__, args, **kwargs)
+
+        for kwarg in kwargs.keys():
+            if not used.get(kwarg):
+                RuntimeException = pyuno.getClass("com.sun.star.uno.RuntimeException")
+                raise RuntimeException("_uno_struct__init__: unused keyword argument '%s'." % kwarg, None)
+
+        self.__dict__["value"] = struct
+
+
+def _uno_struct__getattr__(self, name):
+    """Gets attribute from UNO struct.
+
+    Referenced from the pyuno shared library.
+    """
+
+    return getattr(self.__dict__["value"], name)
+
+
+def _uno_struct__setattr__(self, name, value):
+    """Sets attribute on UNO struct.
+
+    Referenced from the pyuno shared library.
+    """
+
+    return setattr(self.__dict__["value"], name, value)
+
+
+def _uno_struct__repr__(self):
+    """Converts a UNO struct to a printable string.
+
+    Referenced from the pyuno shared library.
+    """
+
+    return repr(self.__dict__["value"])
+
+
+def _uno_struct__str__(self):
+    """Converts a UNO struct to a string."""
+
+    return str(self.__dict__["value"])
+
+
+def _uno_struct__eq__(self, that):
+    """Compares two UNO structs.
+
+    Referenced from the pyuno shared library.
+    """
+
+    if hasattr(that, "value"):
+        return self.__dict__["value"] == that.__dict__["value"]
+
+    return False
+
+
+def _uno_extract_printable_stacktrace(trace):
+    """Extracts a printable stacktrace.
+
+    Referenced from pyuno shared lib and pythonscript.py.
+    """
+
+    return ''.join(traceback.format_tb(trace))
 
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