'csv' is just a string, so when you do dir('csv') it just gives you all the attributes and methods available to str.
If you do dir(csv) (without the quotes) instead you will be able to see all the attributes and methods that the csv module has (providing that you have imported the csv module first):
>>> import csv
>>> dir(csv)
['Dialect', 'DictReader', 'DictWriter', 'Error', 'OrderedDict', 'QUOTE_ALL', 'QUOTE_MINIMAL', 'QUOTE_NONE', 'QUOTE_NONNUMERIC', 'Sniffer', 'StringIO', '_Dialect', '__all__', '__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__spec__', '__version__', 'excel', 'excel_tab', 'field_size_limit', 'get_dialect', 'list_dialects', 're', 'reader', 'register_dialect', 'unix_dialect', 'unregister_dialect', 'writer']