如何调试我的 Python 代码中的问题？

Question

我无法在代码的最后一行正确打印“totalBill”。我不确定如何让它实现用户输入，并且只使用那些 if 约​​束。

# Compute and display the customer bill for water usage during the billing period
# Prompt the user to enter 3 values:
#   a. The customers code (a character)
#   b. The customer's beginning meter reading (a positive integer value)
#   c. The customer's ending meter reading (a positive integer value)
#       Process info and display results

customerCode = str(input("Please enter your customer code: "))
begMeter = int(input("Please enter your beginning meter reading: "))
endMeter = int(input("Please enter your ending meter reading:    "))

waterUsed = endMeter - begMeter

if begMeter > endMeter:
    waterUsedTotal = (((999999999 - begMeter) + 1) + endMeter) /10
else:
    waterUsedTotal = waterUsed * 0.1

a = 4000000
b = 0.00025
d = 10000000
e = 0.0005


if customerCode.lower() == 'r' or 'R':
    totalBill = (5.00 + (waterUsedTotal * e))

elif customerCode.lower() == 'c' or 'C':
    if waterUsed <= a:
        totalBill = 1000.00
    elif waterUsed > a:
        totalBill = (1000.00 + (waterUsedTotal * b))

elif customerCode.lower() == 'i' or 'I':
    if waterUsedTotal <= a:
        totalBill = 1000.00
    elif waterUsed > a and waterUsed <= d:
        totalBill = 2000.00
    elif waterUsed > d:
        totalBill = 2000.00 + (waterUsedTotal * b)

print("")
print("Customer code: ", customerCode)
print("Beginning meter reading: ", begMeter)
print("Ending meter reading:    ", endMeter)
print("Gallons of water used: ", "%.1f" % waterUsedTotal)
print("Amount billed: $", "%.2f" % totalBill)

Answer 1

我注意到的几件事：

if begMeter > endMeter:
    waterUsedTotal = (((999999999 - begMeter) + 1) + endMeter) /10
else:
    waterUsedTotal = waterUsed * 0.1

在第一种情况下，waterUsedTotal 是一个int，即向下舍入。在第二种情况下，它被转换为float。这是不一致的。

更重要的是：

if customerCode.lower() == 'r' or 'R':

此行始终为真，因为'R' 被解释为真。而其他情况是elif，因此它们永远不会被执行。

我怀疑你想要类似的东西：如果用户输入 'r' 或 'R'，则执行此操作，否则如果用户输入 'c' 或 'C' 则执行此操作，否则如果用户输入 @987654331 @ 或 'I' 做最后一件事。

我会建议：

if customerCode in ['r', 'R']:

或

if customerCode.lower() == 'r':

（.lower() 意味着它永远不会是任何大写字符。）