Problems with a def function

[profeteus]

Hello,

Let me start by saying that i have no idea what im doing :). Turned 30, got a kid decided to lern coding for some reason (relly enjoy it so far).

Trying to make a program that roll 3 dices and list the probability in %.
so far i got the following:

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dice_1 = [1, 2, 3, 4, 5, 6] dice_2 = [1, 2, 3, 4, 5, 6] dice_3 = [1, 2, 3, 4, 5, 6]   def roll_dice():     avrage = 0     for x in dice_1:         avrage = x         for y in dice_2:             avrage = x+y             for z in dice_3:                 avrage = x+y+z "

When i run the def i get a list of every possible toss that can be made with 3 t6 dices. How can i now go forward? what im looking for is:

Output:
chance to roll:
3 -> 4%
4 -> 5%
5 -> 7% 
(and so on).

BR
Profeteus

[ichabod801]

What you are going to get at the end of this is nothing. Your function does not return a value. If you put return avrage it would return 18, not the list of values you want. This is because you keep assigning a new value to avrage, over writing what was there before. That's what assignment (=) does.

If you want a list of all the possible values, you need to start with an empty list and append to it:

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die_sides = (1, 2, 3, 4, 5, 6)  # note that I only need one die_sides, and I can loop over it three times.   def roll_dice():     values = []     for die_1 in die_sides:         for die_2 in die_sides:             for die_3 in die_sides:                 values.append(die_1 + die_2 + die_3)     return values

Now, from values you could get the number of times a 3 was rolled with values.count(3). You could divide that by the total number of possible rolls, len(values). But if you are just interested in the # of times each value is rolled, you could count them instead of storing them:

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die_sides = (1, 2, 3, 4, 5, 6)  # note that I only need one die_sides, and I can loop over it three times.   def roll_dice():     counts = [0] * 19    # makes a list of 19 zeros.     for die_1 in die_sides:         for die_2 in die_sides:             for die_3 in die_sides:                 counts[die_1 + die_2 + die_3] += 1   # adds one to the count at that point in the list.     return counts

Now you get the number of times 3 was rolled with counts[3], and the total number of possible rolls is sum(counts).

[ichabod801]

Oh, you can also use itertools to simplify this quite a bit:

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import itertools   die = (1, 2, 3, 4, 5, 6)   def roll():     counts = []     for roll in itertools.product(die, repeat = 3):         counts[sum(roll)] += 1     return counts

[profeteus]

What you are going to get at the end of this is nothing. Your function does not return a value. If you put return avrage it would return 18, not the list of values you want. This is because you keep assigning a new value to avrage, over writing what was there before. That's what assignment (=) does.

If you want a list of all the possible values, you need to start with an empty list and append to it:

1 2 3 4 5 6 7 8 9

die_sides = (1, 2, 3, 4, 5, 6)  # note that I only need one die_sides, and I can loop over it three times.   def roll_dice():     values = []     for die_1 in die_sides:         for die_2 in die_sides:             for die_3 in die_sides:                 values.append(die_1 + die_2 + die_3)     return values

Now, from values you could get the number of times a 3 was rolled with values.count(3). You could divide that by the total number of possible rolls, len(values). But if you are just interested in the # of times each value is rolled, you could count them instead of storing them:

1 2 3 4 5 6 7 8 9

die_sides = (1, 2, 3, 4, 5, 6)  # note that I only need one die_sides, and I can loop over it three times.   def roll_dice():     counts = [0] * 19    # makes a list of 19 zeros.     for die_1 in die_sides:         for die_2 in die_sides:             for die_3 in die_sides:                 counts[die_1 + die_2 + die_3] += 1   # adds one to the count at that point in the list.     return counts

Now you get the number of times 3 was rolled with counts[3], and the total number of possible rolls is sum(counts).

damn, that worked awsome! for the counts = [0] part, how do i turn the awnser into % from this part?

BTW; you are awsome !

[ichabod801]

damn, that worked awsome! for the counts = [0] part, how do i turn the awnser into % from this part?

Like I said, you divide each count by the total number of values. So counts[3] / sum(counts) is the % chance you will roll a three (1 in 216).