The available columns for any given table are fetched from a system table called "sys_tablecolumns". A specific table name is provided in the WHERE criteria to restrict the table from which the column information is fetched:

import cdata.amazonathena as mod
conn = mod.connect("AWSAccessKey='a123';AWSSecretKey='s123';AWSRegion='IRELAND';Database='sampledb';S3StagingDirectory='s3://bucket/staging/';")
cur = conn.cursor()
cmd = "SELECT * FROM sys_tablecolumns WHERE TableName = '[AwsDataCatalog].[sampledb].Customers'"
cur.execute(cmd)
rs = cur.fetchall()
for row in rs:
	print(row)