1 00:00:00,120 --> 00:00:03,090 All right. So now let's tackle hint number 6. 2 00:00:03,660 --> 00:00:06,870 We're going to create a function called calculate_score 3 00:00:06,900 --> 00:00:09,570 that's going to take a list of cards as an input, 4 00:00:09,990 --> 00:00:13,110 and then it returns the score after calculation. 5 00:00:13,890 --> 00:00:16,050 And it tells us that if we get stuck, 6 00:00:16,110 --> 00:00:18,420 we can look up the sum function to help us. 7 00:00:19,080 --> 00:00:22,440 So let's create a function called calculate_score 8 00:00:23,190 --> 00:00:27,720 and this calculate_score is going to take some cards as an input, 9 00:00:28,350 --> 00:00:29,790 and then inside the body 10 00:00:29,820 --> 00:00:34,670 it's going to calculate the total of all the cards in this list. 11 00:00:35,360 --> 00:00:38,780 So if we take a look at the sum function in Python, 12 00:00:39,260 --> 00:00:43,100 the way that it works is you can put a iterable, 13 00:00:43,220 --> 00:00:47,930 so like a list inside the parentheses as an input 14 00:00:48,440 --> 00:00:52,310 and then it's going to add up all of the items in the list 15 00:00:52,640 --> 00:00:56,570 and it's going to return the total. Back in our code 16 00:00:56,870 --> 00:01:00,950 we can simply write sum, and then inside these parentheses 17 00:01:00,980 --> 00:01:05,980 we can pass over the cards and we can return this value as the output. 18 00:01:07,760 --> 00:01:08,450 Basically 19 00:01:08,450 --> 00:01:13,310 if we had cards equal to a list with 1, 5, 20 00:01:13,340 --> 00:01:14,173 3, 21 00:01:14,180 --> 00:01:19,180 4, then the sum function is going to end up being equal to 1 + 5 + 22 00:01:19,580 --> 00:01:23,060 3 + 4, which is going to be equal to 13. 23 00:01:23,360 --> 00:01:26,450 And then that will become the output of this function. 24 00:01:27,530 --> 00:01:29,660 So now let's move on to hint 7. 25 00:01:30,710 --> 00:01:32,660 A Blackjack only happens when 26 00:01:32,740 --> 00:01:37,740 we have a hand with only two cards and those cards have to be an Ace and a 10 27 00:01:39,470 --> 00:01:42,470 value card. In our deck 28 00:01:42,500 --> 00:01:47,500 we know that an Ace is represented by 11 and we have a number of 10 value cards. 29 00:01:50,570 --> 00:01:54,410 So there's a number of ways that we can check for this Blackjack. 30 00:01:54,980 --> 00:01:59,980 One of the ways is by checking to see if the 11 is in our deck of cards, 31 00:02:02,180 --> 00:02:07,180 and then we can combine that with an and to check if the 10 is also in our deck 32 00:02:07,850 --> 00:02:09,800 of cards. And finally, 33 00:02:09,830 --> 00:02:13,730 we can check to make sure that we've got a hand size of two. 34 00:02:14,240 --> 00:02:19,070 So we can check that the length of our cards is equal to two, 35 00:02:19,790 --> 00:02:24,790 and this would represent this logic: a hand with only two cards, an Ace 36 00:02:25,220 --> 00:02:29,900 which is represented by 11 and a 10. Now, on the other hand 37 00:02:29,930 --> 00:02:34,930 we could actually also simplify this because a hand with only two cards that 38 00:02:35,630 --> 00:02:38,600 must contain an 11 and a 10, we can 39 00:02:38,600 --> 00:02:42,380 instead of checking for both 11 and 10, we can check to 40 00:02:42,410 --> 00:02:44,390 see if the total, 41 00:02:44,420 --> 00:02:49,420 so that if we summed the cards and if this was equal to 21, 42 00:02:50,750 --> 00:02:55,010 then it would be exactly the same thing, right? 10 + 11 is 21 43 00:02:55,490 --> 00:02:59,740 and we've still only got a deck of two. In this case 44 00:02:59,770 --> 00:03:04,600 what we want to happen is we want to return zero instead of the actual score. 45 00:03:05,110 --> 00:03:10,110 So this way we can indicate that the user or the computer has got a score of 46 00:03:10,720 --> 00:03:15,010 Blackjack. That's hint number 7 sorted, 47 00:03:15,190 --> 00:03:20,110 let's move onto a hint number 8. It tells us that inside calculate_score, 48 00:03:20,320 --> 00:03:23,770 we should check also for an 11, which is an Ace. 49 00:03:24,400 --> 00:03:26,620 If the score is already over 21, 50 00:03:27,010 --> 00:03:32,010 then we should remove the 11 from the cards and we could replace it with a one, 51 00:03:32,920 --> 00:03:36,940 because remember that an Ace can count as an 11 or 1. 52 00:03:37,420 --> 00:03:41,140 So in the beginning, when the user's score is very small, 53 00:03:41,380 --> 00:03:43,840 then we probably want to count it as an 11. 54 00:03:44,260 --> 00:03:46,690 But once the user goes over 21, 55 00:03:46,960 --> 00:03:50,470 then we probably want to change it and count it as a 1 instead 56 00:03:50,500 --> 00:03:55,000 so they don't go over and they don't lose. Let's first write 57 00:03:55,000 --> 00:03:55,870 the if statement. 58 00:03:56,140 --> 00:04:01,140 So if there is the 11 inside our deck of cards and the 59 00:04:03,670 --> 00:04:08,650 sum of the cards, so the total_score, is already over 21, 60 00:04:09,220 --> 00:04:11,140 then we want to do something about it. 61 00:04:11,680 --> 00:04:15,550 And the hint tells us to look up the append and remove functions. 62 00:04:16,089 --> 00:04:19,180 So we've already seen the append function many times, 63 00:04:19,360 --> 00:04:23,500 and we know that it just adds a single element to the end of the list. 64 00:04:24,520 --> 00:04:28,180 Now the one that we haven't used a lot of is the remove function 65 00:04:28,750 --> 00:04:33,750 and this we'll search for the first instance of the given element and removes it 66 00:04:34,870 --> 00:04:38,260 out of the list. This is kind of what we need to do. 67 00:04:38,590 --> 00:04:43,360 We need to go ahead and remove the 11 from the list of cards. So we can write 68 00:04:43,360 --> 00:04:47,080 cards.remove, and inside the parentheses, 69 00:04:47,380 --> 00:04:52,030 we use the 11 and then we do cards.append, 70 00:04:52,360 --> 00:04:55,960 so that we end up adding a 1 instead of the 11. 71 00:04:56,740 --> 00:05:00,310 This way we remove the 11 and replace it with a 1. 72 00:05:01,210 --> 00:05:05,140 And hopefully our cards will now take the user to below 21.