few leftover changes...

stix2/base.py

@@ -94,7 +94,7 @@ class _STIXBase(Mapping):
         current_properties = self.properties_populated()
         list_of_properties_populated = set(list_of_properties).intersection(current_properties)
 
-        if list_of_properties and (not list_of_properties_populated or list_of_properties_populated == set(['extensions'])):
+        if list_of_properties and (not list_of_properties_populated or list_of_properties_populated == {'extensions'}):
             raise AtLeastOnePropertyError(self.__class__, list_of_properties)
 
     def _check_properties_dependency(self, list_of_properties, list_of_dependent_properties):

stix2/patterns.py

@@ -56,7 +56,7 @@ class TimestampConstant(_Constant):
 
 
 class IntegerConstant(_Constant):
-    """Pattern interger constant
+    """Pattern integer constant
 
     Args:
         value (int): integer value
@@ -265,7 +265,7 @@ class BasicObjectPathComponent(_ObjectPathComponent):
     """Basic object path component (for an observation or expression)
 
     By "Basic", implies that the object path component is not a
-    list, object reference or futher referenced property, i.e. terminal
+    list, object reference or further referenced property, i.e. terminal
     component
 
     Args:

stix2/v20/common.py

@@ -130,7 +130,7 @@ class MarkingDefinition(_STIXBase20, _MarkingsMixin):
     ])
 
     def __init__(self, **kwargs):
-        if set(('definition_type', 'definition')).issubset(kwargs.keys()):
+        if {'definition_type', 'definition'}.issubset(kwargs.keys()):
             # Create correct marking type object
             try:
                 marking_type = OBJ_MAP_MARKING[kwargs['definition_type']]

stix2/v21/common.py

@@ -207,7 +207,7 @@ class MarkingDefinition(_STIXBase21, _MarkingsMixin):
     ])
 
     def __init__(self, **kwargs):
-        if set(('definition_type', 'definition')).issubset(kwargs.keys()):
+        if {'definition_type', 'definition'}.issubset(kwargs.keys()):
             # Create correct marking type object
             try:
                 marking_type = OBJ_MAP_MARKING[kwargs['definition_type']]