[enh] utils: implement a context manager for a SQLite cursor

usage in a with statement [2]::

    with SQLiteCursor('test.db') as cur:
        print(cur.execute('select sqlite_version();').fetchall()[0][0])

[1] https://docs.python.org/3/library/stdtypes.html#context-manager-types
[2] https://docs.python.org/3/reference/compound_stmts.html#with

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

searx/engines/sqlite.py

@@ -6,9 +6,8 @@
 
 """
 
-import sqlite3
-
 from searx import logger
+from searx.utils import SQLiteCursor
 
 logger = logger.getChild('SQLite engine')
 
@@ -19,32 +18,6 @@ limit = 10
 paging = True
 result_template = 'key-value.html'
 
-class SQLiteDB:
-    """
-    Implements a `Context Manager`_ for a SQLite.
-
-    usage::
-
-        with SQLiteDB('test.db') as cur:
-            print(cur.execute('select sqlite_version();').fetchall()[0][0])
-
-    .. _Context Manager: https://docs.python.org/3/library/stdtypes.html#context-manager-types
-    """
-
-    def __init__(self, db):
-        self.database = db
-        self.connect = None
-
-    def __enter__(self):
-        self.connect = sqlite3.connect(self.database)
-        self.connect.row_factory = sqlite3.Row
-        return self.connect.cursor()
-
-    def __exit__(self, exc_type, exc_val, exc_tb):
-        if exc_type is None:
-            self.connect.commit()
-        self.connect.close()
-
 def init(engine_settings):
     if 'query_str' not in engine_settings:
         raise ValueError('query_str cannot be empty')
@@ -64,7 +37,7 @@ def search(query, params):
     }
     query_to_run = query_str + ' LIMIT :limit OFFSET :offset'
 
-    with SQLiteDB(database) as cur:
+    with SQLiteCursor(database) as cur:
 
         cur.execute(query_to_run, query_params)
         col_names = [cn[0] for cn in cur.description]

searx/utils.py

@@ -9,6 +9,7 @@
 import sys
 import re
 import importlib
+import sqlite3
 
 from numbers import Number
 from os.path import splitext, join
@@ -612,3 +613,36 @@ def eval_xpath_getindex(elements, xpath_spec, index, default=NOTSET):
         # to record xpath_spec
         raise SearxEngineXPathException(xpath_spec, 'index ' + str(index) + ' not found')
     return default
+
+class SQLiteCursor:
+    """Implements a `Context Manager`_ for a SQLite *cursor*
+
+    Returns :py:obj:`sqlite3.Cursor` on entering the runtime context of a `with
+    statement`_.
+
+    usage::
+
+        with SQLiteCursor('test.db') as cur:
+            print(cur.execute('select sqlite_version();').fetchall()[0][0])
+
+    .. _Context Manager: https://docs.python.org/3/library/stdtypes.html#context-manager-types
+    .. _with statement: https://docs.python.org/3/reference/compound_stmts.html#with
+
+    """
+
+    def __init__(self, db):
+        self.database = db
+        self.connect = None
+        self.cursor = None
+
+    def __enter__(self):
+        self.connect = sqlite3.connect(self.database)
+        self.connect.row_factory = sqlite3.Row
+        self.cursor = self.connect.cursor()
+        return self.cursor
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        if exc_type is None:
+            self.connect.commit()
+        self.cursor.close()
+        self.connect.close()