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.ebay as mod
conn = mod.connect("DevID=MyDevID;OAuthClientId=MyAppID;OAuthClientSecret=MyCertID;RuName=MyRuName;SiteID=0;OAuthAccessToken=MyOAuthAccessToken")
cur = conn.cursor()
cmd = "SELECT * FROM sys_tablecolumns WHERE TableName = 'ItemListing'"
cur.execute(cmd)
rs = cur.fetchall()
for row in rs:
	print(row)