Take arguments from both stdin and as command-line flags

input.py

#!/usr/bin/env python
# encoding: utf-8

"""
This on the command line
    
    echo '{"d": 44}' | ./input.py --a 33 --b 44 --c

turns into this argument passed to your function
    
    {'a': '33', 'c': True, 'b': '44', u'd': 44}

Of course, mostly you'd just use one or the other, but 
it might come in handy when you want to configure stuff 
over the command-line but send any big blobs of data 
over stdin.
"""

import sys
import functools
import json

## UTILITY CODE ##

def cast(obj):
    """ Currently, no automatic casting from e.g. 
    '1234' to the integer 1234, but I have a 
    module for autocasting I could dust off -- 
    and there's probably others out there too. """
    return obj

def cli(fn):
    @functools.wraps(fn)
    def wrapped_fn():   
        argv = sys.argv[1:]

        if not sys.stdin.isatty():
            stdin = json.loads(sys.stdin.readline())
        else:
            stdin = {}

        pairs = []
        for argument in argv:
            if argument.startswith('--'):
                pairs.append([argument[2:], True])
            else:
                pairs[-1][1] = cast(argument)

        options = {}
        options.update(pairs)
        options.update(stdin)

        return fn(options)

    if __name__ == '__main__':
        wrapped_fn()

    return wrapped_fn

## WHAT THE ACTUAL INTERFACE WOULD LOOK LIKE ##

@cli
def main(options):
    print options