nebula-python

此目录包含Nebula Graph的Python API。它用于连接Nebula Graph 2.0。

开始之前

在开始之前，请阅读本节以选择适合您的分支。在v1.0分支中，API仅适用于Nebula Graph 1.0。在master分支中，API仅适用于Nebula Graph 2.0。

目录结构

|--nebula-python
    |
    |-- nebula2                               // client code
    |   |-- fbthrift                          // the fbthrift lib code
    |   |-- common           
    |   |-- data           
    |   |-- graph           
    |   |-- meta           
    |   |-- net                               // the net code for graph client
    |   |-- storage           
    |   |-- Config.py                         // the pool config
    |   |__ Exception.py                      // the define exception
    |           
    |-- examples
    |   |-- GraphClientMultiThreadExample.py  // the multi thread example
    |   |-- GraphClientSimpleExample.py       // the simple example
    |   |__ ScanVertexEdgeExample.py                   
    |
    |-- tests                                 // the test code
    |                      
    |-- setup.py                              // used to install or package
    |                      
    |__ README.md                             // the introduction of nebula2-python

如何获取nebula2-python

选项一：从GitHub克隆

• 从GitHub克隆

git clone https://github.com/vesoft-inc/nebula-python.git
cd nebula-python

• 安装

sudo python3 setup.py install

当您的环境无法访问pypi时，您需要手动安装以下包。

pip install -r requirements.txt

开发版本

pip install -r requirements-dev.txt

选项二：使用pip

pip install nebula2-python==$version

快速示例：使用graph-client连接graphd

from nebula2.gclient.net import ConnectionPool
from nebula2.Config import Config

# define a config
config = Config()
config.max_connection_pool_size = 10
# init connection pool
connection_pool = ConnectionPool()
# if the given servers are ok, return true, else return false
ok = connection_pool.init([('127.0.0.1', 9669)], config)

# option 1 control the connection release yourself
# get session from the pool
session = connection_pool.get_session('root', 'nebula')

# select space
session.execute('USE nba')

# show tags
result = session.execute('SHOW TAGS')
print(result)

# release session
session.release()

# option 2 with session_context, session will be released automatically
with connection_pool.session_context('root', 'nebula') as session:
    session.execute('USE nba')
    result = session.execute('SHOW TAGS')
    print(result)

# close the pool
connection_pool.close()

快速示例：使用storage-client扫描顶点和边

您应该确保扫描客户端可以连接到从SHOW HOSTS看到的存储地址

from nebula2.mclient import MetaCache, HostAddr
from nebula2.sclient.GraphStorageClient import GraphStorageClient

# the metad servers's address
meta_cache = MetaCache([('172.28.1.1', 9559),
                        ('172.28.1.2', 9559),
                        ('172.28.1.3', 9559)],
                       50000)

# option 1 metad usually discover the storage address automatically
graph_storage_client = GraphStorageClient(meta_cache)

# option 2 manually specify the storage address
storage_addrs = [HostAddr(host='172.28.1.4', port=9779),
                 HostAddr(host='172.28.1.5', port=9779),
                 HostAddr(host='172.28.1.6', port=9779)]
graph_storage_client = GraphStorageClient(meta_cache, storage_addrs)

resp = graph_storage_client.scan_vertex(
        space_name='ScanSpace',
        tag_name='person')
while resp.has_next():
    result = resp.next()
    for vertex_data in result:
        print(vertex_data)
        
resp = graph_storage_client.scan_edge(
    space_name='ScanSpace',
    edge_name='friend')
while resp.has_next():
    result = resp.next()
    for edge_data in result:
        print(edge_data)

如何选择nebula-python