the problem is with the list of args that write can't handle.

You might want to use:

file.write('\n'.join(sys.argv[1:]))

Not something I'd do, but you could use inspect.signature to introspect the arguments your method takes:

>>> import inspect
>>> def foobar(foo, bar, baz):
...     return inspect.signature(foobar)
... 
>>> foobar(1, 2, 3)
<Signature (foo, bar, baz)>

The returned Signature instance has an ordered collection of parameters (the .parameters attribute) which can then be used together with locals() to produce a list of your argument values:

>>> def foobar(foo, bar, baz):
...     sig, foobar_locals = inspect.signature(foobar), locals()
...     return [foobar_locals[param.name] for param in sig.parameters.values()]
...
>>> foobar(1, 2, 3)
[1, 2, 3]

However, you really only need such magic when doing advanced function decorators and the like. I think it's overkill here.

I highly recommend argparse which comes with Python 2.7 and later.

The argparse module reduces boiler plate code and makes your code more robust, because the module handles all standard use cases (including subcommands), generates the help and usage for you, checks and sanitize the user input - all stuff you have to worry about when you are using sys.argv approach. And it is for free (built-in).

Here a small example:

import argparse

parser = argparse.ArgumentParser("simple_example")
parser.add_argument("counter", help="An integer will be increased by 1 and printed.", type=int)
args = parser.parse_args()
print(args.counter + 1)

and the output for python prog.py -h

usage: simple_example [-h] counter
    
positional arguments:
  counter     counter will be increased by 1 and printed.
    
optional arguments:
  -h, --help  show this help message and exit

and the output for python prog.py 1 As one would expect:

2

The inspect module is extremely powerful. To get a list of classes, for example in the csv module, you could go:

import inspect, csv
from pprint import pprint

module = csv
mod_string = 'csv'
module_classes = inspect.getmembers(module, inspect.isclass)
for i in range(len(module_classes)):
  myclass = module_classes[i][0]
  myclass = mod_string+'.'+myclass
  myclass = eval(myclass)
  # could construct whatever query you want about this class here...
  # you'll need to play with this line to get what you want; it will failasis
  #line = inspect.formatargspect(*inspect.getfullargspec(myclass))
  pprint(myclass)

Hope this helps get you started!

The canonical solution in the standard library is argparse (docs):

Here is an example:

from argparse import ArgumentParser

parser = ArgumentParser()
parser.add_argument("-f", "--file", dest="filename",
                    help="write report to FILE", metavar="FILE")
parser.add_argument("-q", "--quiet",
                    action="store_false", dest="verbose", default=True,
                    help="don't print status messages to stdout")

args = parser.parse_args()

argparse supports (among other things):

• Multiple options in any order.
• Short and long options.
• Default values.
• Generation of a usage help message.