I’ve been taking a beginner python class to help cement what I already know and fill in the gaps of what I don’t know.
Tonight, we learned about data structures. The instructor mentioned that you can multiply lists. Like, some_list * 5
Can someonehelp me out with an example of how you could use this?
For me it seems that this isn't a plain python list but numpy.
stackoverflow.com
list = [1, 2, 3]
result = list * 2
# result = [2, 4, 6]
numpy would give that result, but plain python should make the list repeat.For me it seems that this isn't a plain python list but numpy.
How do I multiply each element in a list by a number?
I have a list: my_list = [1, 2, 3, 4, 5] How can I multiply each element in my_list by 5? The output should be: [5, 10, 15, 20, 25]
The result will be:
Python:list = [1, 2, 3] result = list * 2 # result = [2, 4, 6]
numbers = [0, 1, 2] * 3 # prints [0, 1, 2, 0, 1, 2, 0, 1, 2]
Why should I want this? 😅 Really, I NEVER had the case, in my whole 13 years, to repeat a list. 🤔🤯
Okay, i found a case when this could be useful - weighted random list retrieve.
common * 5 + epic * 2 + legendary
Very clever. 🧙♂️
Right!? That's why I asked.
characters = [common, common, common, common, common, epic, epic, legendary] ?I think I could imagine that being potentially useful.
Yeah, it's the most basic approach to code item drop chances. We do this in game-jams.
common = [ 'stick', 'heal-pot', 'mana-pot' ]
epic = [ 'epic-sword', 'epic-shield' ]
legendary = [ 'deathbringer' ]
pool = common * 5 + epic * 2 + legendary
# pool = stick, stick, stick, stick, stick, heal-pot, heal-pot, heal-pot, heal-pot, heal-pot, mana-pot, mana-pot, mana-pot, mana-pot, mana-pot, epic-sword, epic-sword, epic-shield, epic-shield, deathbringer
item = pool.shuffle().random()shuffle() will mix all items in list and random() will take a random item from list.
We do it another way to have more control - we use an array:
$items = [
'stick' => 6,
'heal-pot' => 5,
'mana-pot' => 4,
'shield' => 2,
'sword' => 3,
'deathbringer' => 1,
'clothing' => 4,
];
$pool = [];
foreach($items as $item => $amount) {
$pool = $pool + array_fill(0, $amount, $item);
}