使用Python将BigQuery模式表转换为json

我需要这个BigQueryBQshow-format=prettyjson myproject:mydataset.mytable的Python等价物

有没有办法用Python中的BigQueryAPI实现这一点

我在Python中尝试了以下方法：

view_ref = self._client.dataset(dataset.dataset_id).table(table.table_id)
table_obj = self._client.get_table(view_ref)

dict_schema = []
for schema_field in table_obj.schema:
    dict_schema.append({
        'name': schema_field.name,
        'mode': schema_field.mode,
        'type': schema_field.field_type
   })

它几乎起作用了；我只是没有嵌套的模式字段/

---

感谢您的回复，祝您度过愉快的一天。

您可以使用该方法将表模式转换为json。它需要两个属性，分别是schema_list和destination

我用一个带有嵌套数据的公共数据集举例说明了您的案例，并仅用于说明模式将如何

from google.cloud import bigquery
import io

client = bigquery.Client()

project = 'bigquery-public-data'
dataset_id = 'samples'
table_id = 'shakespeare'

dataset_ref = client.dataset(dataset_id, project=project)
table_ref = dataset_ref.table(table_id)
table = client.get_table(table_ref)


f = io.StringIO("")
client.schema_to_json(table.schema, f)
print(f.getvalue())

以及输出：

[
  {
    "description": "A single unique word (where whitespace is the delimiter) extracted from a corpus.",
    "mode": "REQUIRED",
    "name": "word",
    "type": "STRING"
  },
  {
    "description": "The number of times this word appears in this corpus.",
    "mode": "REQUIRED",
    "name": "word_count",
    "type": "INTEGER"
  },
  {
    "description": "The work from which this word was extracted.",
    "mode": "REQUIRED",
    "name": "corpus",
    "type": "STRING"
  },
  {
    "description": "The year in which this corpus was published.",
    "mode": "REQUIRED",
    "name": "corpus_date",
    "type": "INTEGER"
  }
]

---

这与使用命令时显示的输出相同！bq show-format=prettyjson bigquery公共数据：samples.wikipedia | jq.schema.fields'

您可以使用该方法将表模式转换为json。它需要两个属性，分别是schema_list和destination

我用一个带有嵌套数据的公共数据集举例说明了您的案例，并仅用于说明模式将如何

from google.cloud import bigquery
import io

client = bigquery.Client()

project = 'bigquery-public-data'
dataset_id = 'samples'
table_id = 'shakespeare'

dataset_ref = client.dataset(dataset_id, project=project)
table_ref = dataset_ref.table(table_id)
table = client.get_table(table_ref)


f = io.StringIO("")
client.schema_to_json(table.schema, f)
print(f.getvalue())

以及输出：

[
  {
    "description": "A single unique word (where whitespace is the delimiter) extracted from a corpus.",
    "mode": "REQUIRED",
    "name": "word",
    "type": "STRING"
  },
  {
    "description": "The number of times this word appears in this corpus.",
    "mode": "REQUIRED",
    "name": "word_count",
    "type": "INTEGER"
  },
  {
    "description": "The work from which this word was extracted.",
    "mode": "REQUIRED",
    "name": "corpus",
    "type": "STRING"
  },
  {
    "description": "The year in which this corpus was published.",
    "mode": "REQUIRED",
    "name": "corpus_date",
    "type": "INTEGER"
  }
]

这与使用命令时显示的输出相同！bq show-format=prettyjson bigquery公共数据：samples.wikipedia | jq'.schema.fields'