initial creation

py3interm/EXAMPLES/db_sqlite_bulk_insert.py

@@ -0,0 +1,96 @@
+#!/usr/bin/env python
+import os
+import sqlite3
+import random
+
+FRUITS = ["pomegranate", "cherry", "apricot", "date", "apple",
+          "lemon", "kiwi", "orange", "lime", "watermelon", "guava",
+          "papaya", "fig", "pear", "banana", "tamarind", "persimmon",
+          "elderberry", "peach", "blueberry", "lychee", "grape"]
+
+DB_NAME = 'fruitprices.db'  # <1>
+
+CREATE_TABLE = """
+create table fruit (
+    name varchar(30),
+    price decimal
+)
+"""  # <2>
+
+INSERT = '''
+insert into fruit (name, price) values (?, ?)
+'''  # <3>
+
+
+def main():
+    """
+    Program entry point.
+
+    :return: None
+    """
+    conn = get_connection()
+    create_database(conn)
+    populate_database(conn)
+
+    read_database()
+
+
+def get_connection():
+    """
+    Get a connection to the PRODUCE database
+
+    :return: SQLite3 connection object.
+    """
+    if os.path.exists(DB_NAME):
+        os.remove(DB_NAME)  # <4>
+
+    s3conn = sqlite3.connect(DB_NAME)  # <5>
+    return s3conn
+
+
+def create_database(conn):
+    """
+    Create the fruit table
+
+    :param conn: The database connection
+    :return: None
+    """
+    conn.execute(CREATE_TABLE)  # <6>
+
+
+def populate_database(conn):
+    """
+    Add rows to the fruit table
+
+    :param conn: The database connection
+    :return: None
+    """
+
+    fruit_data = get_fruit_data()  # [('apple', .49), ('kiwi', .38)]
+
+    try:
+        conn.executemany(INSERT, fruit_data)  # <7>
+    except sqlite3.DatabaseError as err:
+        print(err)
+        conn.rollback()
+    else:
+        conn.commit()  # <8>
+
+
+def get_fruit_data():
+    """
+    Create iterable of fruit records.
+
+    :return: Generator of name/price tuples.
+    """
+    return ((f, round(random.random() * 10 + 5, 2)) for f in FRUITS)  # <9>
+
+
+def read_database():
+    conn = sqlite3.connect(DB_NAME)
+    for name, price in conn.execute('select name, price from fruit'):
+        print('{:12s} {:6.2f}'.format(name, price))
+
+
+if __name__ == '__main__':
+    main()