Python：如何从字典中随机选择的键中获取值

Question

What I'm trying to do here is to get a random choice from a list

races = ['Dragonborn', 'Dwarf', 'Elf', 'Gnome', 'Half-Elf', 'Halfling', 'Half-Orc', 'Human', 'Tiefling']
races_choice = random.choice(races)

and then use that random choice from the list to look at keys in a separate dictionary

subraces = {
'Dwarf': ['Hill Dwarf', 'Mountain Dwarf'],
'Elf': ['High Elf', 'Wood Elf', 'Dark Elf'], 
'Halfling': ['Lightfoot', 'Stout'], 
'Gnome': ['Forest Gnome', 'Rock Gnome'],
}

and if that key matches the random choice, print a random value from that key.

I've tried a few things, but what I'm currently on is this:

if races_choice == subraces.keys():
    print(random.choice(subraces.values[subraces.keys]))

But this returns nothing. I'm a bit at a loss for how to do this.

Thank you.

Answer 1

You can simply use .get on the dictionary.

DEFAULT_VALUE = "default value"
subraces = {
       'Dwarf': ['Hill Dwarf', 'Mountain Dwarf'],
       'Elf': ['High Elf', 'Wood Elf', 'Dark Elf'], 
       'Halfling': ['Lightfoot', 'Stout'], 
       'Gnome': ['Forest Gnome', 'Rock Gnome'],
}

races = ['Dragonborn', 'Dwarf', 'Elf', 'Gnome', 'Half-Elf', 
        'Halfling', 
        'Half-Orc', 'Human', 'Tiefling']

races_choice = random.choice(races)
subrace_options = subraces.get(races_choice, DEFAULT_VALUE)
if subrace_options != DEFAULT_VALUE:
    index = random.randint(0, (len(subrace_options) - 1))
    print(subrace_options[index])
else: 
    print("No subrace for specified race")

This will yield the name of a subrace from a given race eg for Dwarf the output will be a random entry in the list ie Hill Dwarf .

The string value in the .get is the default value which will be assigned if the key (the random choice) cannot be found in your map of subraces.

Answer 2

It seems like you can simply set a random int equivalent to the length of items accordingly to the key

import random

races = ['Dragonborn', 'Dwarf', 'Elf', 'Gnome', 'Half-Elf', 'Halfling', 'Half-Orc', 'Human', 'Tiefling']

races_choice = random.choice(races)

subraces = {
'Dwarf': ['Hill Dwarf', 'Mountain Dwarf'],
'Elf': ['High Elf', 'Wood Elf', 'Dark Elf'],
'Halfling': ['Lightfoot', 'Stout'],
'Gnome': ['Forest Gnome', 'Rock Gnome']}

if races_choice in subraces:
    print(subraces[races_choice][random.randint(0, len(subraces[races_choice]) - 1)])  # -1 since lists starts from 0, not 1
else:
    print('"' + races_choice + '"', 'has no subraces')

Answer 3

you also can try something like this:

from random import choice

print(choice(subraces.get(choice(races),[0])) or 'no matches')