Automatically roll out a D&D (5e) attribute layout using a method described by Matthew Colville

matt_colville_att_gen.py

#!/usr/bin/env python
"""
Copyright 2017 Daniel Gill

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Automatically roll out a D&D (5e) attribute layout using the method
described by Matthew Colville here:

    https://youtu.be/0K9mKpAMREU?t=8m53s

Put simply, 4d6 drop lowest for each attribute in order (i.e. first
roll is str, second is dex, etc.), rerolling the entire layout if 
at least two of the attributes are not 15 or higher.
"""
import random

d6 = lambda: random.randint(1, 6)

def roll_att():
    rollout = (d6(), d6(), d6(), d6())
    return sum(rollout) - min(rollout)

def rollout_attributes():
    return {
        'str': roll_att(),
        'dex': roll_att(),
        'con': roll_att(),
        'int': roll_att(),
        'wis': roll_att(),
        'cha': roll_att()
    }

def attributes_are_valid(attributes):
    over_fifteen = filter(lambda attr: attr >= 15, attributes.values())
    return len(list(over_fifteen)) >= 2

def main():
    attributes = rollout_attributes()
    while not attributes_are_valid(attributes):
        attributes = rollout_attributes()
    
    modifiers = {}
    for attribute, value in attributes.items():
        modifiers[attribute + '_mod'] = (value - 10) // 2

    attributes.update(modifiers)

    print('''\
    str: {str} ({str_mod:+d})
    dex: {dex} ({dex_mod:+d})
    con: {con} ({con_mod:+d})
    int: {int} ({int_mod:+d})
    wis: {wis} ({wis_mod:+d})
    cha: {cha} ({cha_mod:+d})\
    '''.format(**attributes))

if __name__ == '__main__':
    main()