如何在for循环中更改列表？ Python中的Labouchere

Question

I'm going through a text on elementary probability theory, http://www.dartmouth.edu/~chance/teaching_aids/books_articles/probability_book/amsbook.mac.pdf , as a refresher and using it as an opportunity to teach myself some programming.

I'm trying to write a simulation for a Labouchere betting system in roulette (question 9 page# 13 in the linked pdf).

I think that I am close to the right answer but I can't figure out how to get the list 'bet' to change for each successive round.

Here is what I have so far:

    def Labouchere(T):
        bet, mon = [4,3,2,1], 0
        for t in range(0,T):
            ball = random.uniform(0.0,1.0)
            if ball < (18/float(38)):
                mon += (bet[0] + bet[-1])
                np.delete(bet, 0, 0)
                np.delete(bet, -1, 0)
            elif ball >= (18/float(38)):
                mon -= (bet[0] + bet[-1])
                np.insert(bet, 0, (bet[0]+bet[-1]))
            else:
                break
        return mon

Any help is much appreciated. I am also trying to learn from Steven F. Lott's book 'Building Skills in Object-Oriented Design' but it seems to be above my level of understanding so far. A recommendation for material that would prep me for using that guide would also be invaluable.

Thanks in advance.

Answer 1

In the winning case, either:

bet = bet[1:-1] # "slice" from second to penultimate

or:

bet.pop(0) # remove first
bet.pop(-1) # remove last

In your losing case:

bet.append(mon) # add to end

Answer 2

You can use slicing and append to achieve this. See Explain Python's slice notation for more details.

If the user wins:

list = list[1:len(list)-1]

If the user loses:

list.append(list[0] + list[len(list)-1])