3 Funcionalidades do MongoDB subutilizadas

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coll.insert_one(
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    {
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        "name": "Professor Bagura",
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        # This document will disappear before 2022:
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        "expires_at": datetime.fromisoformat("2021-12-31 23:59:59"),
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    }
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)
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# Retrieve a valid document by filtering on docs where `expires_at` is in the future:
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if (doc := coll.find_one({"expires_at": {"$gt": datetime.now()}})) is None:
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    # If no valid documents exist, create one (and probably store it):
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    doc = create_document()
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# Code to use the retrieved or created document goes here.
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print(doc)

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while True:
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    # Delete all documents where `expires_at` is in the past:
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    coll.delete_many({"expires_at": {"$lt": datetime.now()}})
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    time.sleep(60)

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coll = db.get_collection("ttl_collection")
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# Creates a new index on the `created_at`.
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# The document will be deleted when current time reaches one hour (3600 seconds)
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# after the date stored in `created_at`:
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coll.create_index([("expires_at", 1)], expireAfterSeconds=3600)
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coll.insert_one(
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    {
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        "name": "Professor Bagura",
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        "created_at": datetime.now(),  # Document will disappear after one hour.
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    }
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)

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coll = db.get_collection("expiry_collection")
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# Creates a new index on the `expires_at`.
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# The document will be deleted when
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# the current time reaches the date stored in `expires_at`:
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coll.create_index([("expires_at", 1)], expireAfterSeconds=0)
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coll.insert_one(
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    {
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        "name": "Professor Bagura",
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        # This document will disappear before 2022:
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        "expires_at": datetime.fromisoformat("2021-12-31 23:59:59"),
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    }
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)

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# Create acollection with a large size value that will store a max of 3 docs:
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coll = db.create_collection("capped", capped=True, size=1000000, max=3)
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# Insert 3 docs:
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coll.insert_many([{"name": "Chico"}, {"name": "Harpo"}, {"name": "Groucho"}])
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# Insert a fourth doc! This will evict the oldest document to make space (Zeppo):
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coll.insert_one({"name": "Zeppo"})
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# Print out the docs in the collection:
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for doc in coll.find():
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    print(doc)
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# {'_id': ObjectId('600e8fcf36b07f77b6bc8ecf'), 'name': 'Harpo'}
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# {'_id': ObjectId('600e8fcf36b07f77b6bc8ed0'), 'name': 'Groucho'}
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# {'_id': ObjectId('600e8fcf36b07f77b6bc8ed1'), 'name': 'Zeppo'}

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with my_database.my_collection.watch() as stream:
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    for change in stream:
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        print(change)