Restrict elementpath exceptions usage to ElementPathError

- Use only the base exception, others are derivation also of
    built-in exceptions.

xmlschema/validators/facets.py

@@ -13,7 +13,7 @@ This module contains declarations and classes for XML Schema constraint facets.
 """
 from __future__ import unicode_literals
 import re
-from elementpath import XPath2Parser, ElementPathSyntaxError, ElementPathTypeError, datatypes
+from elementpath import XPath2Parser, ElementPathError,  datatypes
 
 from ..compat import unicode_type, MutableSequence
 from ..qnames import XSD_LENGTH, XSD_MIN_LENGTH, XSD_MAX_LENGTH, XSD_ENUMERATION, XSD_WHITE_SPACE, \
@@ -665,7 +665,7 @@ class XsdAssertionFacet(XsdFacet):
 
         try:
             self.token = self.parser.parse(self.path)
-        except (ElementPathSyntaxError, ElementPathTypeError) as err:
+        except ElementPathError as err:
             self.parse_error(err, elem=self.elem)
             self.token = self.parser.parse('true()')
 

xmlschema/validators/identities.py

@@ -14,7 +14,7 @@ This module contains classes for other XML Schema identity constraints.
 from __future__ import unicode_literals
 import re
 from collections import Counter
-from elementpath import Selector, XPath1Parser, ElementPathSyntaxError, ElementPathKeyError
+from elementpath import Selector, XPath1Parser, ElementPathError
 
 from ..exceptions import XMLSchemaValueError
 from ..qnames import XSD_UNIQUE, XSD_KEY, XSD_KEYREF, XSD_SELECTOR, XSD_FIELD
@@ -66,7 +66,7 @@ class XsdSelector(XsdComponent):
 
         try:
             self.xpath_selector = Selector(self.path, self.namespaces, parser=XsdIdentityXPathParser)
-        except (ElementPathSyntaxError, ElementPathKeyError) as err:
+        except ElementPathError as err:
             self.parse_error(err)
             self.xpath_selector = Selector('*', self.namespaces, parser=XsdIdentityXPathParser)