mirror of
https://github.com/sqlalchemy/sqlalchemy.git
synced 2026-05-07 17:31:24 -04:00
Mike Bayer
1e278de4cc
Applied on top of a pure run of black -l 79 in I7eda77fed3d8e73df84b3651fd6cfcfe858d4dc9, this set of changes resolves all remaining flake8 conditions for those codes we have enabled in setup.cfg. Included are resolutions for all remaining flake8 issues including shadowed builtins, long lines, import order, unused imports, duplicate imports, and docstring issues. Change-Id: I4f72d3ba1380dd601610ff80b8fb06a2aff8b0fe
80 lines
1.8 KiB
Python
80 lines
1.8 KiB
Python
"""a directed graph example."""
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from sqlalchemy import Column
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from sqlalchemy import create_engine
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from sqlalchemy import ForeignKey
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from sqlalchemy import Integer
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from sqlalchemy.ext.declarative import declarative_base
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from sqlalchemy.orm import relationship
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from sqlalchemy.orm import sessionmaker
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Base = declarative_base()
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class Node(Base):
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__tablename__ = "node"
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node_id = Column(Integer, primary_key=True)
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def higher_neighbors(self):
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return [x.higher_node for x in self.lower_edges]
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def lower_neighbors(self):
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return [x.lower_node for x in self.higher_edges]
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class Edge(Base):
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__tablename__ = "edge"
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lower_id = Column(Integer, ForeignKey("node.node_id"), primary_key=True)
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higher_id = Column(Integer, ForeignKey("node.node_id"), primary_key=True)
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lower_node = relationship(
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Node, primaryjoin=lower_id == Node.node_id, backref="lower_edges"
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)
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higher_node = relationship(
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Node, primaryjoin=higher_id == Node.node_id, backref="higher_edges"
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)
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def __init__(self, n1, n2):
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self.lower_node = n1
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self.higher_node = n2
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engine = create_engine("sqlite://", echo=True)
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Base.metadata.create_all(engine)
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session = sessionmaker(engine)()
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# create a directed graph like this:
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# n1 -> n2 -> n1
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# -> n5
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# -> n7
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# -> n3 -> n6
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n1 = Node()
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n2 = Node()
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n3 = Node()
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n4 = Node()
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n5 = Node()
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n6 = Node()
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n7 = Node()
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Edge(n1, n2)
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Edge(n1, n3)
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Edge(n2, n1)
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Edge(n2, n5)
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Edge(n2, n7)
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Edge(n3, n6)
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session.add_all([n1, n2, n3, n4, n5, n6, n7])
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session.commit()
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assert [x for x in n3.higher_neighbors()] == [n6]
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assert [x for x in n3.lower_neighbors()] == [n1]
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assert [x for x in n2.lower_neighbors()] == [n1]
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assert [x for x in n2.higher_neighbors()] == [n1, n5, n7]
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