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.saparibaprocurement as mod
conn = mod.connect("ANID=AN02000000280;API=PurchaseOrdersBuyerAPI-V1;APIKey=wWVLn7WTAXrIRMAzZ6VnuEj7Ekot5jnU;AuthScheme=OAuthClient;InitiateOAuth=GETANDREFRESH;OAuthClientId=testClient;OAuthClientSecret=testClientSecret;UseSandbox=false;")
cur = conn.cursor()
cmd = "SELECT * FROM sys_tablecolumns WHERE TableName = 'Orders'"
cur.execute(cmd)
rs = cur.fetchall()
for row in rs:
	print(row)