Best practice for lazy loading Python modules

Question

Occasionally I want lazy module loading in Python. Usually because I want to keep runtime requirements or start-up times low and splitting the code into sub-modules would be cum

Answer 1

Nice pattern from sqlalchemy: dependency injection:

@util.dependencies("sqlalchemy.orm.query")
def merge_result(query, *args):
    #...
    query.Query(...)

Instead of declaring all "import" statements at the top of the module, it will only import a module when it's actually needed by a function. This can resolve circular dependency problems.