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我可以使用 avro-tools-1.7.7.jar 获取 json 数据和 avro 模式并输出二进制 Avro 文件，如下所示https://github.com/miguno/avro-cli-examples#json-to -avro。但是，我希望能够使用 Avro python api 以编程方式执行此操作：https ://avro.apache.org/docs/1.7.7/gettingstartedpython.html 。

在他们的示例中，他们展示了如何一次将记录写入二进制 avro 文件。

    import avro.schema
    from avro.datafile import DataFileReader, DataFileWriter
    from avro.io import DatumReader, DatumWriter

    schema = avro.schema.parse(open("user.avsc").read())

    writer = DataFileWriter(open("users.avro", "w"), DatumWriter(), schema)
    writer.append({"name": "Alyssa", "favorite_number": 256})
    writer.append({"name": "Ben", "favorite_number": 7, "favorite_color": "red"})
    writer.close()

我的用例是一次写入所有记录，就像 avro-tools jar 从 json 文件中所做的那样，只是在 python 代码中。我不想掏空并执行 jar。如果这很重要，这将被部署到 Google App Engine。

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1 回答 1

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这可以通过fastavro. 例如，给定链接中的架构：

推特.avsc

{
  "type" : "record",
  "name" : "twitter_schema",
  "namespace" : "com.miguno.avro",
  "fields" : [ {
    "name" : "username",
    "type" : "string",
    "doc" : "Name of the user account on Twitter.com"
  }, {
    "name" : "tweet",
    "type" : "string",
    "doc" : "The content of the user's Twitter message"
  }, {
    "name" : "timestamp",
    "type" : "long",
    "doc" : "Unix epoch time in seconds"
  } ],
  "doc:" : "A basic schema for storing Twitter messages"
}

和 json 文件：

推特.json

{"username":"miguno","tweet":"Rock: Nerf paper, scissors is fine.","timestamp": 1366150681 }
{"username":"BlizzardCS","tweet":"Works as intended.  Terran is IMBA.","timestamp": 1366154481 }

您可以使用类似以下脚本的内容来写出 avro 文件：

import json
from fastavro import json_reader, parse_schema, writer

with open("twitter.avsc") as fp:
    schema = parse_schema(json.load(fp))

with open("twitter.avro", "wb") as avro_file:
    with open("twitter.json") as fp:
        writer(avro_file, schema, json_reader(fp, schema))
于 2021-01-21T15:12:58.297 回答