Python pymssql error "TypeError: argument of type 'NoneType' is not iterable" when connecting to SQL server -

i getting error "typeerror: argument of type 'nonetype' not iterable" when attempting connect sql server. believe error being generated on line connect sql server itself, second print statement never used, though wrong.

i using pymysql-2.1.3, , python 3.5.1

server = getenv("####") user = getenv("####") password = getenv("####") database = getenv("####")  print("hi") conn = pymssql.connect(server, user, password, database) print("hi2") cursor = conn.cursor()  cursor.execute("####"                "select name, sourcetable, sourcetableid dbo.attachment name '%icad%'")   conn.close() print("connect sql complete") 

this results in error:

traceback (most recent call last): hi   file "c:/convert.py", line 62, in <module>     connect_to_sql()   file "c:convert.py", line 15, in connect_to_sql     conn = pymssql.connect(server, user, password, database)   file "pymssql.pyx", line 635, in pymssql.connect (pymssql.c:10734)   file "_mssql.pyx", line 1902, in _mssql.connect (_mssql.c:21821)   file "_mssql.pyx", line 552, in _mssql.mssqlconnection.__init__ (_mssql.c:5891) typeerror: argument of type 'nonetype' not iterable  process finished exit code 1 

i have no idea why happening - connect function follows pymssql documentation exactly.

i importing following libraries if helps:

import os os import getenv import pymssql import subprocess 

i have removed database credentials in question, know work able connect sql server via management studio.

does know why code doesn't work?

this code contained within function called 'connect_to_sql():' , used afterwards, of following code sensitive have cut these particular lines out. hope enough.