Python: What is SQLAlchemy?

1from sqlalchemy import create_engine, Column, Integer, String, ForeignKey
2from sqlalchemy.orm import declarative_base, relationship, Session
3
4Base = declarative_base()
5
6# Model
7class User(Base):
8    __tablename__ = "users"
9    id = Column(Integer, primary_key=True)
10    name = Column(String(50))
11    orders = relationship("Order", back_populates="user")
12
13class Order(Base):
14    __tablename__ = "orders"
15    id = Column(Integer, primary_key=True)
16    user_id = Column(Integer, ForeignKey("users.id"))
17    user = relationship("User", back_populates="orders")
18
19# Queries
20engine = create_engine("sqlite:///db.sqlite")
21Base.metadata.create_all(engine)
22
23with Session(engine) as session:
24    # Create
25    user = User(name="Alice")
26    session.add(user)
27    session.commit()
28
29    # Read
30    user = session.query(User).filter_by(name="Alice").first()
31
32    # Update
33    user.name = "Bob"
34    session.commit()
35
36    # Delete
37    session.delete(user)
38    session.commit()