为什么我的程序不计算最后一场比赛的分数？

Question

I want to input scores of 30 matches of football game and calculate the number of the winning match and total scores. I have 30 input but it doesn't calculate the last match (30th match). What am I to do?

scores=0
win_number=0
game_number=0
x=int(input())
count=0
while count!=30 :
    if x==3:
        scores=scores+3
        win_number=win_number+1
        game_number=game_number+1
        count=count+1
        x=int(input())
    elif x==1:
        scores=scores+1
        win_number=win_number+1
        x=int(input())
        count=count+1
    elif x==0:
        game_number=game_number+1
        count=count+1
        x=int(input())
else :
    print(scores,'',win_number,game_number)

Answer 1

I will make a simplified use case to explain why your code doesnt work as you think. Imagine we only want 1 score. you set count to 0 and read the first input before your loop. So you have taken the input before the loop started. At this point the count is still set as 0. So you start your loop count != 1 . This takes the input you collected outside the loop and adds to the stats. It then increments the count by 1 so the count now equals 1. You then ask for the input again. This second input is given (even though you only wanted 1 match). this input is stored in x and the first iteration of the loop ends. the loop condition count!=1 is now broken so the loop finishes after 1 iteration. so the second input which is allocated to x is never added to the stats. Which is the correct behaviour. The issue is your code structure meant that you would ask for 1 more input but never count the last one and still get 30 matches

Instead you can use a range to generate X number of iterations. Your code can also be cleaned up as there are a lot of lines that occur in each if statement these can be removed from the if and just written once in the loop.

scores=0
win_number = 0
game_number = 0
for _ in range(3):
    x = int(input('score: '))
    scores += x
    if x == 3 or x == 1:
        win_number=win_number+1
    if x == 3 or x == 0:
        game_number += 1

print(scores,win_number,game_number)

CONSOLE

score: 3
score: 1
score: 0
4 2 2

Answer 2

Had a little fun refactoring your code. This is what I came up with:

count = 0
scores = 0
win_number = 0
game_number = 0

while count < 30:
    x = int(input())
    if x not in [0, 1, 3]:
        print("Wrong input - enter either 0, 1 or 3")
        continue
    scores += x
    count += 1
    game_number += 1

    if x == 3 or x == 1: # is x == 1 really a win, though?
        win_number = win_number+1

    print(scores,'',win_number,game_number)