Python List random choice

问题

Looking for a help / solution here.

a = [1,2,3]
b = [1,2,3]
c = [1,2,3]
d = [a,b,c]

random.choice(random.choice(d))

this gives me 1,2 or 3. But how to find which list variable this random function used out of a, b, c ? how can I use or what is the syntax of the index function for this ? for my program I have to pop the element the random choice returns.

回答1:

If you want to remove something from the randomly chosen list, you don't need to have the variable name. The list object itself will do.

In other words, just remove the selected number from the result that random.choice() gives you:

picked_list = random.choice(d)
picked = random.choice(picked_list)
picked_list.remove(picked)

If you must have some kind of name, don't use separate variables for the input lists. Use a dictionary:

lists = {
    'a': [1, 2, 3],
    'b': [1, 2, 3],
    'c': [1, 2, 3],
}
list_picked = random.choice(lists)  # returns 'a', 'b', or 'c'
picked = random.choice(lists[list_picked])
lists[list_picked].remove(picked)

Note that it'll be more efficient to just shuffle your lists up-front (putting them in random order), then pop elements as you need them:

d = [a, b, c]
for sublist in d:
    random.shuffle(sublist)

# later on
picked = random.choice(d).pop()  # remove the last element

You'll have to figure out what it means to have an empty list there though.

来源：https://stackoverflow.com/questions/44355406/python-list-random-choice