I'm struggling with implementing the Bridge design pattern (or an alternative such as Adapter) in Python

I want to be able to write code like this to dump database schemas based on a supplied URL:

urls = ['sqlite://c:\\temp\\test.db', 'oracle://user:password@tns_name'];
for url in urls:
    db = Database(url);
    schema = db.schema()

I've got classes defined as

class Database():
    def __init__(self, url):
        self.db_type = string.split(self.url, "://")[0]

class Oracle():
    def schema(self):
        # Code to return Oracle schema

class SQLite():
    def schema(self):
        # Code to return SQLite schema

How can I "glue" these 3 classes together so I can get the first code block to execute correctly? I've Googled around, but must be having a thick day as it's just not coming together in my mind...

Thanks in advance

python design-patterns
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