在Python中，在while循环中附加列表会出现错误消息“List index out of range”

Question

所以我试着做一个简单的循环，出于某种原因，我似乎不明白为什么会出现错误消息

earnings = [94500,65377,84524]
deductions = [20000,18000,19000]

tax = [] #empty list
i = -1    #iterative counter
while True:
    i=i+1
    if (earnings[i] > 23000):
        tax.append(0.14*earnings[i])
        continue
    else:
        break
print ('Tax calculation has been completed')
print ('Number of iterations: ',i)

我觉得这跟线路有关 if (earnings[i] > 23000)但我不知道该如何处理这个问题

Answer 1

您可以使用enumerate在earnings列表上迭代，同时生成从1开始的迭代计数器：

tax = []
for i, earning in enumerate(earnings, 1):
    if earning <= 23000:
        break
    tax.append(0.14 * earning)

print('Tax calculation has been completed')
print('Number of iterations: ', i)

Answer 2

在循环中没有检查索引是否超出范围的检查，即检查i与列表“收益”中的项数。请这样做：

earnings = [94500,65377,84524]
deductions = [20000,18000,19000]

tax = [] #empty list
i = -1    #iterative counter
while True:
    i=i+1
    if i >= len(earnings):
        break
    if (earnings[i] > 23000):
        tax.append(0.14*earnings[i])
        continue
print ('Tax calculation has been completed')
print ('Number of iterations: ',i)