py2no: graph.cypher.execute()

Question

有没有办法让这个功能更nice/readerble？（例如，格式化字符串，这样我就没有 "create .." + label + "..."）

from py2neo import Graph

graph = Graph()

def create_node(label, properties):
    """Create a note with the label-type and some properties"""
    graph.cypher.execute("CREATE (p:" + label + " " + properties + ")")

create_node("Person", "{name: 'Alice', age: '22'}")

Answer 1

你有没有想过使用py2neo的内置方法？你会做

from py2neo import Node
alice = Node("Person", name="Alice", age=22)

如果你确实想使用 Cypher，它会有点不雅，因为你不能参数化标签。我还建议传递 Python 字典作为属性而不是字符串：

def create_node(label, properties):
    query = "CREATE (:{}".format(label) + " {properties})"
    params = dict(properties=properties)
    graph.cypher.execute(query, params)

create_node("Person", {"name":"Alice","age":22})

之所以"CREATE (:{} {})".format(label, properties)不起作用是因为字典的键会被引号括起来，这是无效的Cypher。例如：

>>> d = dict(name="Alice",age=22)
>>> label = "Person"
>>> "CREATE (:{} {})".format(label, properties)
"CREATE (:Person {'age': 22, 'name': 'Alice'})"

这将引发错误，因为有效的 Cypher 将是：

"CREATE (:Person {age: 22, name: 'Alice'})"

py2no: graph.cypher.execute()

Py2Neo: graph.cypher.execute()

python

neo4j

cypher

py2neo