Using Python Docopt (for beautiful command-line interfaces) I recently had the problem of converting a list of tuples into a dictionary. In this post I’d like to document the solution I came up with…

    mytool [options]

    --foo-bar=PARAM1,PARAM2,... params to do stuff with
        [default: key1.value1,key1.value2,key2.value2]

from docopt import docopt
from collections import defaultdict

def run():
    params = [tuple(param.strip().split('.')) for param in arguments["--foo-bar"].split(",")]
    params = convert_tuple_list_to_dictionary(ignored_resources)

def convert_tuple_list_to_dictionary(list_of_tuple):
    dictionary = defaultdict(list)
    for k, v in list_of_tuple:

    return dictionary

if __name__ == "__main__":

This code is able to convert the parameter value string key1.value1,key1.value2,key2.value2 into the following dictionary:

	'key1': ['value1', 'value2'],
    'key2': ['value2']

If you know a leaner solution to solve this problem, please write a comment!

Jan Brennenstuhl

Jan is a software engineer, web security enthusiast & clean code artist. He lives in Berlin, is currently working for Zalando SE and loves his bonsai trees, coffee & road cycling.

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