database.py

class CtatDatabase:
    def __init__(self):
        self.data = {}

    def set(self, key, value):
        self.data[key] = value

    def get(self, key):
        return self.data.get(key)

    def delete(self, key):
        if key in self.data:
            del self.data[key]

    def list_keys(self):
        return list(self.data.keys())

    def clear(self):
        self.data.clear()

# Example Usage:
if __name__ == "__main__":
    db = CtatDatabase()

    db.set("name", "ctat")
    db.set("language", "Python")
    db.set("version", "1")

    print("Name:", db.get("name"))
    print("Language:", db.get("language"))

    print("Keys:", db.list_keys())

    db.delete("version")

    print("Keys after deletion:", db.list_keys())

    db.clear()

    print("Keys after clearing:", db.list_keys())