bpo-43396: Normalise naming in sqlite3 doc examples (GH-24746)

(cherry picked from commit 40d1b831ec)

Co-authored-by: Erlend Egeberg Aasland <erlend.aasland@innova.no>

Doc/library/sqlite3.rst

@@ -25,34 +25,34 @@ represents the database.  Here the data will be stored in the
 :file:`example.db` file::
 
    import sqlite3
-   conn = sqlite3.connect('example.db')
+   con = sqlite3.connect('example.db')
 
 You can also supply the special name ``:memory:`` to create a database in RAM.
 
 Once you have a :class:`Connection`, you can create a :class:`Cursor`  object
 and call its :meth:`~Cursor.execute` method to perform SQL commands::
 
-   c = conn.cursor()
+   cur = con.cursor()
 
    # Create table
-   c.execute('''CREATE TABLE stocks
+   cur.execute('''CREATE TABLE stocks
                   (date text, trans text, symbol text, qty real, price real)''')
 
    # Insert a row of data
-   c.execute("INSERT INTO stocks VALUES ('2006-01-05','BUY','RHAT',100,35.14)")
+   cur.execute("INSERT INTO stocks VALUES ('2006-01-05','BUY','RHAT',100,35.14)")
 
    # Save (commit) the changes
-   conn.commit()
+   con.commit()
 
    # We can also close the connection if we are done with it.
    # Just be sure any changes have been committed or they will be lost.
-   conn.close()
+   con.close()
 
 The data you've saved is persistent and is available in subsequent sessions::
 
    import sqlite3
-   conn = sqlite3.connect('example.db')
+   con = sqlite3.connect('example.db')
-   c = conn.cursor()
+   cur = con.cursor()
 
 Usually your SQL operations will need to use values from Python variables.  You
 shouldn't assemble your query using Python's string operations because doing so
@@ -67,19 +67,19 @@ example::
 
    # Never do this -- insecure!
    symbol = 'RHAT'
-   c.execute("SELECT * FROM stocks WHERE symbol = '%s'" % symbol)
+   cur.execute("SELECT * FROM stocks WHERE symbol = '%s'" % symbol)
 
    # Do this instead
    t = ('RHAT',)
-   c.execute('SELECT * FROM stocks WHERE symbol=?', t)
+   cur.execute('SELECT * FROM stocks WHERE symbol=?', t)
-   print(c.fetchone())
+   print(cur.fetchone())
 
    # Larger example that inserts many records at a time
    purchases = [('2006-03-28', 'BUY', 'IBM', 1000, 45.00),
                 ('2006-04-05', 'BUY', 'MSFT', 1000, 72.00),
                 ('2006-04-06', 'SELL', 'IBM', 500, 53.00),
                ]
-   c.executemany('INSERT INTO stocks VALUES (?,?,?,?,?)', purchases)
+   cur.executemany('INSERT INTO stocks VALUES (?,?,?,?,?)', purchases)
 
 To retrieve data after executing a SELECT statement, you can either treat the
 cursor as an :term:`iterator`, call the cursor's :meth:`~Cursor.fetchone` method to
@@ -88,7 +88,7 @@ matching rows.
 
 This example uses the iterator form::
 
-   >>> for row in c.execute('SELECT * FROM stocks ORDER BY price'):
+   >>> for row in cur.execute('SELECT * FROM stocks ORDER BY price'):
            print(row)
 
    ('2006-01-05', 'BUY', 'RHAT', 100, 35.14)
@@ -768,23 +768,23 @@ Row Objects
 
 Let's assume we initialize a table as in the example given above::
 
-   conn = sqlite3.connect(":memory:")
+   con = sqlite3.connect(":memory:")
-   c = conn.cursor()
+   cur = con.cursor()
-   c.execute('''create table stocks
+   cur.execute('''create table stocks
    (date text, trans text, symbol text,
     qty real, price real)''')
-   c.execute("""insert into stocks
+   cur.execute("""insert into stocks
                values ('2006-01-05','BUY','RHAT',100,35.14)""")
-   conn.commit()
+   con.commit()
-   c.close()
+   cur.close()
 
 Now we plug :class:`Row` in::
 
-   >>> conn.row_factory = sqlite3.Row
+   >>> con.row_factory = sqlite3.Row
-   >>> c = conn.cursor()
+   >>> cur = con.cursor()
-   >>> c.execute('select * from stocks')
+   >>> cur.execute('select * from stocks')
    <sqlite3.Cursor object at 0x7f4e7dd8fa80>
-   >>> r = c.fetchone()
+   >>> r = cur.fetchone()
    >>> type(r)
    <class 'sqlite3.Row'>
    >>> tuple(r)