bad argument type for built-in operation

[Florian Lindner]

Hello,
I've the traceback:

Traceback (most recent call last):
  File "visualizer.py", line 8, in ?
    main()
  File "visualizer.py", line 5, in main
    g = GraphCreator(f)
  File "/home/florian/visualizer/GraphCreator.py", line 13, in __init__
    self.conf = ConfigReader(config)
  File "/home/florian/visualizer/ConfigReader.py", line 53, in __init__
    graph.sourceReader = CSVReader(filename, firstline, delimiter)
  File "/home/florian/visualizer/ConfigReader.py", line 13, in __init__
    self.reader = csv.reader(f, delimiter=Adelimiter)
TypeError: bad argument type for built-in operation

f ist file object, Adelimiter is ",".

What is wrong there?

Thanks,
Florian