How to get the table definition in a database from AWS Glue Data Catalog using Boto3

Let's see how a user can retrieve the definition of all tables or some of the tables that are matching as per regular expression in a database from AWS Glue Data Catalog.

Example

Retrieve table definition of all tables in a database 'QA-test' and table as 'security', and 'employee'.

Approach/Algorithm to solve this problem

• Step 1: Import boto3 and botocore exceptions to handle the exceptions.

• Step 2: database_name is the mandatory parameter while regular_expression_for_table_name is the optional parameter. If the user wants to fetch the details of all tables, then there's no need to provide the regular expression. However, if only limited tables need to be fetched, then a regular expression is required. Be careful while writing the regular expression as the result might change if it is not written properly.

• Step 3: Create an AWS session using boto3 lib. Make sure region_name is mentioned in default profile. If it is not mentioned, then explicitly pass the region_name while creating the session.

• Step 4: Create an AWS client for glue.

• Step 5: Now use get_tables function and pass the database_name as DatabaseName and regular_expression_for_table_name as Expression parameter.

• Step 6: It returns the definition of all or matched tables in a given database.

• Step 7: Handle the generic exception if something went wrong while checking the job.

Example Code

The following code retrieves all the table definitions from a given database −

import boto3
from botocore.exceptions import ClientError

def retrieves_tables_detail(database_name, regular_expression_for_table_name=None)
   session = boto3.session.Session()
   glue_client = session.client('glue')
   try:
      response = glue_client.get_tables(DatabaseName = database_name, Expression=regular_expression_for_table_name)                        
      return response
   except ClientError as e:
      raise Exception(
         "boto3 client error in retrieves_tables_detail: " + e.__str__())
   except Exception as e:
      raise Exception(
         "Unexpected error in retrieves_tables_detail: " + e.__str__())
print(retrieves_tables_detail('QA-test'))

Output

{'TableList': [
{'Name': 'security', 'DatabaseName': 'QA-test', 'Owner': 'owner', 'CreateTime': datetime.datetime(2020, 9, 10, 22, 27, 24, tzinfo=tzlocal()), 'UpdateTime': datetime.datetime(2021, 3, 1, 11, 43, 49, tzinfo=tzlocal()), 'LastAccessTime': datetime.datetime(2020, 9, 10, 22, 27, 24, tzinfo=tzlocal()), 'Retention': 0, 'StorageDescriptor': {'Columns': [{'Name': 'assettypecode', 'Type': 'string'}, {'Name': 'industrysector', 'Type': 'varchar'}, {'Name': 'securitycode', 'Type': 'char'}, {'Name': 'contractsize', 'Type': 'string'}, {'Name': 'conversionperiodenddate', 'Type': 'string'}, {'Name': 'conversionperiodstartdate', 'Type': 'string'}, {'Name': 'expirationdate', 'Type': 'string'}, {'Name': 'issuercountrycode', 'Type': 'string'}, {'Name': 'issuercountrydesc', 'Type': 'string'}, {'Name': 'originalissuedate', 'Type': 'string'}, {'Name': 'securitynamelong', 'Type': 'string'}, {'Name': 'issueshortname', 'Type': 'string'}, {'Name': 'gicssector', 'Type': 'string'}, {'Name': 'maturitydate', 'Type': 'string'}, {'Name': 'optioncode', 'Type': 'string'}, {'Name': 'optiontypename', 'Type': 'string'}, {'Name': 'paramount', 'Type': 'string'}, {'Name': 'priceindex', 'Type': 'string'}, {'Name': 'countrycoderisk', 'Type': 'string'}, {'Name': 'countrydescrisk', 'Type': 'string'}, {'Name': 'countrycode', 'Type': 'string'}], 'Location': 's3://test/security/', 'InputFormat': 'org.apache.hadoop.hive.ql.io.parquet.MapredParquetInputFormat', 'OutputFormat': 'org.apache.hadoop.hive.ql.io.parquet.MapredParquetOutputFormat', 'Compressed': False, 'NumberOfBuckets': -1, 'SerdeInfo': {'SerializationLibrary': 'org.apache.hadoop.hive.ql.io.parquet.serde.ParquetHiveSerDe', 'Parameters': {'serialization.format': '1'}}, 'BucketColumns': [], 'SortColumns': [], 'Parameters': {'CrawlerSchemaDeserializerVersion': '1.0', 'CrawlerSchemaSerializerVersion': '1.0', 'UPDATED_BY_CRAWLER': 'security', 'averageRecordSize': '181', 'classification': 'parquet', 'compressionType': 'none', 'objectCount': '5', 'recordCount': '154800', 'sizeKey': '20337230', 'typeOfData': 'file'}, 'StoredAsSubDirectories': False}, 'PartitionKeys': [], 'TableType': 'EXTERNAL_TABLE', 'Parameters': {'CrawlerSchemaDeserializerVersion': '1.0', 'CrawlerSchemaSerializerVersion': '1.0', 'UPDATED_BY_CRAWLER': 'security', 'averageRecordSize': '181', 'classification': 'parquet', 'compressionType': 'none', 'objectCount': '5', 'recordCount': '154800', 'sizeKey': '20337230', 'typeOfData': 'file'}, 'CreatedBy': 'arn:aws:sts::*********:assumed-role/glue-role/AWS-Crawler'}, 'VersionId': '2'},
{'Name': 'employee', 'DatabaseName': 'QA-test', 'Owner': 'owner', 'CreateTime': datetime.datetime(2020, 9, 10, 22, 27, 24, tzinfo=tzlocal()), 'UpdateTime': datetime.datetime(2021, 3, 1, 11, 43, 49, tzinfo=tzlocal()), 'LastAccessTime': datetime.datetime(2020, 9, 10, 22, 27, 24, tzinfo=tzlocal()), 'Retention': 0, 'StorageDescriptor': {'Columns': [{'Name': 'assettypecode', 'Type': 'string'}, {'Name': 'industrysector', 'Type': 'varchar'}, {'Name': 'code', 'Type': 'char'}, {'Name': 'size', 'Type': 'string'}, {'Name': 'countrycode', 'Type': 'string'}, {'Name': 'countrydesc', 'Type': 'string'}], 'Location': 's3://test/security/', 'InputFormat': 'org.apache.hadoop.hive.ql.io.parquet.MapredParquetInputFormat', 'OutputFormat': 'org.apache.hadoop.hive.ql.io.parquet.MapredParquetOutputFormat', 'Compressed': False, 'NumberOfBuckets': -1, 'SerdeInfo': {'SerializationLibrary': 'org.apache.hadoop.hive.ql.io.parquet.serde.ParquetHiveSerDe', 'Parameters': {'serialization.format': '1'}}, 'BucketColumns': [], 'SortColumns': [], 'Parameters': {'CrawlerSchemaDeserializerVersion': '1.0', 'CrawlerSchemaSerializerVersion': '1.0', 'UPDATED_BY_CRAWLER': 'security', 'averageRecordSize': '181', 'classification': 'parquet', 'compressionType': 'none', 'objectCount': '5', 'recordCount': '154800', 'sizeKey': '20337230', 'typeOfData': 'file'}, 'StoredAsSubDirectories': False}, 'PartitionKeys': [], 'TableType': 'EXTERNAL_TABLE', 'Parameters': {'CrawlerSchemaDeserializerVersion': '1.0', 'CrawlerSchemaSerializerVersion': '1.0', 'UPDATED_BY_CRAWLER': 'employee', 'averageRecordSize': '181', 'classification': 'parquet', 'compressionType': 'none', 'objectCount': '5', 'recordCount': '154800', 'sizeKey': '20337230', 'typeOfData': 'file'}, 'CreatedBy': 'arn:aws:sts::*********:assumed-role/glue-role/AWS-Crawler'}, 'VersionId': '2'}, 'ResponseMetadata': {'RequestId': '431db171-*******************0', 'HTTPStatusCode': 200, 'HTTPHeaders': {'date': 'Mon, 01 Mar 2021 06:15:30 GMT', 'content-type': 'application/x-amz-json-1.1', 'content-length': '3916', 'connection': 'keep-alive', 'x-amzn-requestid': '431db171-*****************0'}, 'RetryAttempts': 0}}