python random choice against multiple lists

Question

I’m having trouble explaining this so please bare with me.

I have several lists and I want to write a python script that picks an item at random from the first list, then checks that result against a "fail list," if the item isn’t on the "fail list" I want to move to the next list and do the same thing until it fails.

#Go through these lists one by one, picking random item. 
action_heros = ['thor', 'batman', 'spiderman', 'superbart']
friends = ['joey', 'feebee', 'rachael', 'dog']
himym = ['robin', 'marshall', 'ted', 'lily', 'barney']


# fail list
simpsons = ['bart', 'homer', 'marg', 'superbart', 'dog', 'barney']


#This is how I've been trying to solve it, but I can't get the code to move to the second or third attempt 

# pick a random word from the lists
rand_action_hero = random.choice(action_heros)
rand_friend = random.choice(friends)
rand_himym = random.choice(himym)

#run the random word from each list against the checklist one by one until it fails. 
if rand_action_hero in simpsons:
    print('failed at actionheros')
#if the random word isn't in simpsons I want it to pick a new random word and try against friend, then himym

Thanks for any help, I’m still learning to code so it means a lot!

Asked By: Nate

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Source

Answer 1

Put all your choices into a list, then loop through them testing if it’s in the fail list.

for listname, choice in [('action_heros', rand_action_hero), ('friends', rand_friend), ('himym', rand_himym)]: 
    if choice in simpsons:
        print(f'failed at {listname}')
        break
else:
    print('All tests succeeded')

You could avoid hard-coding all the list names and variables by turning the separate lists into a dictionary.

Answered By: Barmar

Answer 2

Instead of repeatedly picking a new choice, I’d suggest removing all items in the fail-list from your input.

For example:

action_heros = [item for item in ['thor', 'batman', 'spiderman', 'superbart'] if item not in simpsons]

['thor', 'batman', 'spiderman']

This makes sure you always get a valid choice.

simpsons = ['bart', 'homer', 'marg', 'superbart', 'dog', 'barney']
action_heros = ['thor', 'batman', 'spiderman', 'superbart']
random.choice([item for item in action_heros if item not in simpsons])

You can do the same by converting your input to sets and use the setdifference:

random.choice(tuple(set(action_heros) - set(simpsons)))

Answered By: bitflip

Answer 3

If you know about hash sets, I would use a set for the fail list for faster lookups although it is unnecessary.

Other than that, this code should work.

import random

#Go through these lists one by one, picking random item. 
action_heros = ['thor', 'batman', 'spiderman', 'superbart']
friends = ['joey', 'feebee', 'rachael', 'dog']
himym = ['robin', 'marshall', 'ted', 'lily', 'barney']


# fail list
simpsons = set(['bart', 'homer', 'marg', 'superbart', 'dog', 'barney'])

# loop until it breaks
while 1:
    rand_action_hero = random.choice(action_heros)
    print(rand_action_hero)
    if rand_action_hero in simpsons:
        print("random action hero in fail list")
        break
    
    rand_friend = random.choice(friends)
    print(rand_friend)
    if rand_friend in simpsons:
        print("random friend in fail list")
        break

    rand_himym = random.choice(himym)
    print(rand_himym)
    if rand_himym in simpsons:
        print("random himym in fail list")
        break

Answered By: Jon Smith

Answer 4

Explanation:

We first create a dictionary with all the lists combined with their respectful title, and we loop over each element in that dictionary and compare a random.choice() from that element with the fail_list. and if it exists in the fail list we continue the loop, now if it doesn’t exist in the loop we break/stop that loop.

My code:

import random

lists = {"action heros":['thor', 'batman', 'spiderman', 'superbart'],
         "friends":['joey', 'feebee', 'rachael', 'dog'],
         "himym":['robin', 'marshall', 'ted', 'lily', 'barney']}

fail_list = ['bart', 'homer', 'marg', 'superbart', 'dog', 'barney']


for elements in lists:
  if random.choice(lists[elements]) in fail_list:
    continue
  else:
    print("failed at {0}".format(elements))
    break

Output

code won’t have any fixed output since it runs with a random.choice() but…

>>> failed at himym

Diagram

Answered By: Fahim Ferdous

python random choice against multiple lists

Question:

Answers:

Explanation:

My code:

Output

Diagram