diff --git a/cubicweb_elasticsearch/hooks.py b/cubicweb_elasticsearch/hooks.py
index 2902d5c817cf57296ae3f82e53479b7beed394c4_Y3ViaWN3ZWJfZWxhc3RpY3NlYXJjaC9ob29rcy5weQ==..bf3a2a7007d10b04353a986302f691c3eb5189ef_Y3ViaWN3ZWJfZWxhc3RpY3NlYXJjaC9ob29rcy5weQ== 100644
--- a/cubicweb_elasticsearch/hooks.py
+++ b/cubicweb_elasticsearch/hooks.py
@@ -24,7 +24,7 @@
 
 
 def entity_indexable(entity):
-    """ returns boolean to indicate if entity is indexable """
+    """returns boolean to indicate if entity is indexable"""
     return (
         entity.cw_etype in indexable_types(entity._cw.vreg.schema)
         or entity.cw_adapt_to("IFullTextIndexSerializable").custom_indexable_attributes
@@ -72,7 +72,7 @@
 
 
 class IndexEsOperation(hook.DataOperationMixIn, hook.Operation):
-    """ mixin class to process ES indexing as a postcommit event """
+    """mixin class to process ES indexing as a postcommit event"""
 
     containercls = list
 
diff --git a/cubicweb_elasticsearch/search_helpers.py b/cubicweb_elasticsearch/search_helpers.py
index 2902d5c817cf57296ae3f82e53479b7beed394c4_Y3ViaWN3ZWJfZWxhc3RpY3NlYXJjaC9zZWFyY2hfaGVscGVycy5weQ==..bf3a2a7007d10b04353a986302f691c3eb5189ef_Y3ViaWN3ZWJfZWxhc3RpY3NlYXJjaC9zZWFyY2hfaGVscGVycy5weQ== 100644
--- a/cubicweb_elasticsearch/search_helpers.py
+++ b/cubicweb_elasticsearch/search_helpers.py
@@ -19,7 +19,7 @@
 
 from elasticsearch_dsl import Q, query as dsl_query
 
-SIMPLE_QUERY_OPERATORS = "|+-\"()*~"
+SIMPLE_QUERY_OPERATORS = '|+-"()*~'
 SIMPLE_QUERY_OPERATORS_RE = r"[\|\+\-\"\(\)\*\~]"
 
 
@@ -41,8 +41,7 @@
     ~N after a word signifies edit distance (fuzziness)
     ~N after a phrase signifies slop amount
 
-    https://www.elastic.co/guide/en/elasticsearch/reference/7.9/query-dsl-simple-query-string-query.html
-"""
+    https://www.elastic.co/guide/en/elasticsearch/reference/7.9/query-dsl-simple-query-string-query.html"""  # noqa
     # for all operators except "-", if it appears, then we assume it is a simple query
     for operator in SIMPLE_QUERY_OPERATORS.replace("-", ""):
         if operator in query:
@@ -89,10 +88,7 @@
 
     if is_simple_query_string(query):
         query_string = Q(
-            "simple_query_string",
-            query=query,
-            fields=fields,
-            default_operator="and"
+            "simple_query_string", query=query, fields=fields, default_operator="and"
         )
         should.append(query_string)
 
@@ -101,11 +97,7 @@
             phrase = common = True
         if phrase:
             phrase_query = Q(
-                "multi_match",
-                query=query,
-                type="phrase",
-                slop=50,
-                fields=fields
+                "multi_match", query=query, type="phrase", slop=50, fields=fields
             )
             should.append(phrase_query)
         # highfrequency/lowfrequency query
@@ -125,7 +117,7 @@
         elements = re.sub(SIMPLE_QUERY_OPERATORS_RE, " ", query).split()
         for element in elements:
             if fuzzy:
-                should.append(dsl_query.Fuzzy(alltext=element.replace('"', '')))
+                should.append(dsl_query.Fuzzy(alltext=element.replace('"', "")))
     bool_query = dsl_query.Bool(
         must=must,
         must_not=must_not,