Improve pylint to 10.0

gramps/plugins/db/dbapi/sqlite.py

@@ -18,19 +18,35 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 #
 
-import os
+"""
+Backend for sqlite database.
+"""
+
+#-------------------------------------------------------------------------
+#
+# standard python modules
+#
+#-------------------------------------------------------------------------
 import sqlite3
 import logging
 import re
 
 sqlite3.paramstyle = 'qmark'
 
+#-------------------------------------------------------------------------
+#
+# Sqlite class
+#
+#-------------------------------------------------------------------------
 class Sqlite:
+    """
+    The Sqlite class is an interface between the DBAPI class which is the Gramps
+    backend for the DBAPI interface and the sqlite3 python module.
+    """
     @classmethod
     def get_summary(cls):
         """
-        Return a diction of information about this database
+        Return a dictionary of information about this database backend.
-        backend.
         """
         summary = {
             "DB-API version": "2.0",
@@ -43,6 +59,18 @@ class Sqlite:
         return summary
 
     def __init__(self, *args, **kwargs):
+        """
+        Create a new Sqlite instance.
+
+        This connects to a sqlite3 database and creates a cursor instance.
+
+        :param args: arguments to be passed to the sqlite3 connect class at
+                     creation.
+        :type args: list
+        :param kwargs: arguments to be passed to the sqlite3 connect class at
+                       creation.
+        :type kwargs: list
+        """
         self.log = logging.getLogger(".sqlite")
         self.connection = sqlite3.connect(*args, **kwargs)
         self.cursor = self.connection.cursor()
@@ -50,35 +78,84 @@ class Sqlite:
         self.connection.create_function("regexp", 2, regexp)
 
     def execute(self, *args, **kwargs):
+        """
+        Executes an SQL statement.
+
+        :param args: arguments to be passed to the sqlite3 execute statement
+        :type args: list
+        :param kwargs: arguments to be passed to the sqlite3 execute statement
+        :type kwargs: list
+        """
         self.log.debug(args)
         self.cursor.execute(*args, **kwargs)
 
     def fetchone(self):
+        """
+        Fetches the next row of a query result set, returning a single sequence,
+        or None when no more data is available.
+        """
         return self.cursor.fetchone()
 
     def fetchall(self):
+        """
+        Fetches the next set of rows of a query result, returning a list. An
+        empty list is returned when no more rows are available.
+        """
         return self.cursor.fetchall()
 
     def begin(self):
+        """
+        Start a transaction manually. This transactions usually persist until
+        the next COMMIT or ROLLBACK command.
+        """
         self.log.debug("BEGIN TRANSACTION;")
         self.execute("BEGIN TRANSACTION;")
 
     def commit(self):
+        """
+        Commit the current transaction.
+        """
         self.log.debug("COMMIT;")
         self.connection.commit()
 
     def rollback(self):
+        """
+        Roll back any changes to the database since the last call to commit().
+        """
         self.log.debug("ROLLBACK;")
         self.connection.rollback()
 
     def table_exists(self, table):
+        """
+        Test whether the specified SQL database table exists.
+
+        :param table: table name to check.
+        :type table: str
+        :returns: True if the table exists, false otherwise.
+        :rtype: bool
+        """
         self.execute("SELECT COUNT(*) FROM sqlite_master "
                      "WHERE type='table' AND name='%s';" % table)
         return self.fetchone()[0] != 0
 
     def close(self):
+        """
+        Close the current database.
+        """
         self.log.debug("closing database...")
         self.connection.close()
 
 def regexp(expr, value):
+    """
+    A user defined function that can be called from within an SQL statement.
+
+    This function has two parameters.
+
+    :param expr: pattern to look for.
+    :type expr: str
+    :param value: the string to search.
+    :type value: list
+    :returns: True if the expr exists within the value, false otherwise.
+    :rtype: bool
+    """
     return re.search(expr, value, re.MULTILINE) is not None