Using Python to Operate db4o

Db4o is an open source object-oriented database that can be used with Python. Here are the steps to connect, insert, query, modify, and delete db4o databases using Python: 1. Install dependency libraries: First, you need to install Python's db4o library. You can install by running the following command from the command line: shell pip install db4o 2. Connect to the database: Next, you can use the db4o library to connect to the database. Before connecting, a database file needs to be created first. The following is an example code for connecting to a database: python from db4o import * database = Db4o.openFile("path/to/database.db4o") 3. Insert Data: Once the connection is successful, data can be inserted into the database. The following is an example code for inserting data: python class Person(object): def __init__(self, name, age): self.name = name self.age = age person = Person("John", 25) database.store(person) 4. Query data: You can use the query function of db4o to retrieve data from the database. The following is an example code for querying data: python query = database.query() Query. train (Person) # Specify the object type for the query Query. descent ("name"). train ("John") # Specify query criteria result = query.execute() for person in result: print(person.name, person.age) 5. Modify data: You can use the update function of db4o to modify the data in the database. The following is an example code for modifying data: python query = database.query() query.constrain(Person) query.descend("name").constrain("John") result = query.execute() for person in result: person.age = 30 database.store(person) 6. Delete data: You can use the delete function of db4o to delete data from the database. The following is an example code for deleting data: python query = database.query() query.constrain(Person) query.descend("name").constrain("John") result = query.execute() for person in result: database.delete(person) 7. Close database connection: After all operations are completed, the database connection needs to be closed. The following is an example code to close a database connection: python database.close() The above is a complete Python code example that shows how to connect to a db4o database, insert, query, modify, and delete data. Please adjust the database file path, object type, and query criteria in the code according to the actual situation.