当我使用“%.2f”时，出现 "a float is required" 错误，为什么？

Question

我正在为学校做一个项目，最后我要总结客户（用户）账单。

如果我删除“%.2f”，则不会收到错误消息，但显示的数字会一直显示。如何只显示最后 2 位小数？

我使用的代码：

print('Amount Due:        $' + '%.2f' % baseCharge)

我收到的输出：

    print('Amount Due:        $' + '%.2f' % baseCharge)
TypeError: a float is required

完整代码：


rentalCode = input("(B)udget, (D)aily, or (W)eekly rental?\n")

weeksRented = 0
daysRented = 0
budgetCharge = 40
dailyCharge = 60
weeklyCharge = 190


if rentalCode == 'B' or rentalCode == 'D':
  daysRented = input("Number of Days Rented:") #Prompt --> "Number of Days Rented:"
else:
    weeksRented = input("Number of Weeks Rented:\n") #Prompt --> "Number of Weeks Rented:"

odoStart = int(input("Starting Odometer Reading:\n"))
odoEnd = int(input("Ending Odometer Reading:\n"))
totalMiles = odoEnd - odoStart

print(rentalCode) # Displays Chosen Rental Code
if rentalCode == 'B' or rentalCode == 'D': # Decides which option has been input and displays the output
  print(daysRented)
else:
  print(weeksRented)

baseCharge = 0
if rentalCode == 'B':
  baseCharge = daysRented * budgetCharge
elif rentalCode == 'D':
  baseCharge = daysRented * dailyCharge
elif rentalCode == 'W':
  baseCharge = weeksRented * weeklyCharge



#Print odoStart, odoEnd and totalMiles
print(odoStart)
print(odoEnd)
print(totalMiles)
# Calculate Charges 2

totalCharge = 0
if rentalCode == 'B':
  totalCharge = baseCharge + str(totalMiles * .25)
elif rentalCode == 'D':
  averageDayMiles = int(totalMiles) / int(daysRented)
  if averageDayMiles <= 100:
    totalCharge = baseCharge
  else:
    extraMiles = totalMiles - 100
    totalCharge = baseCharge + str(extraMiles * .25)
elif rentalCode == 'W':
  averageWeekMiles = int(totalMiles) / int(weeksRented)
  if averageWeekMiles <= 900:
    totalCharge = baseCharge
  else:
    totalCharge = baseCharge + str(weeksRented * 100)

print(totalCharge)

if rentalCode == "W":
    rentalPeriod = weeksRented
else:
    rentalPeriod = daysRented

print(rentalPeriod)

if rentalCode == "B":
    baseCharge = budgetCharge * rentalPeriod
elif rentalCode == "D":
    baseCharge = dailyCharge * rentalPeriod
else:
    baseCharge = weeklyCharge * rentalPeriod




print('Customer Summary')
print('Rental Code:       ' + rentalCode)
print('Rental Period:     ' + rentalPeriod)
print('Starting Odometer: ' + str(odoStart))
print('Ending Odometer:   ' + str(odoEnd))
print('Miles Driven:      ' + str(totalMiles))
print('Amount Due:        $' + '%.2f' % baseCharge)

同样，如果那个 %.2f 就位，我会收到输出错误，但如果我把它去掉，我会收到一个大数字。例子：而不是 951.65 我会得到 951.6555555555555555555 等等

Answer 1

rentalCode = input("(B)udget, (D)aily, or (W)eekly rental?\n")

weeksRented = 0
daysRented = 0
budgetCharge = 40
dailyCharge = 60
weeklyCharge = 190


if rentalCode == 'B' or rentalCode == 'D':
  daysRented = int(input("Number of Days Rented:")) #Prompt --> "Number of Days Rented:"
else:
    weeksRented = int(input("Number of Weeks Rented:\n")) #Prompt --> "Number of Weeks Rented:"

odoStart = int(input("Starting Odometer Reading:\n"))
odoEnd = int(input("Ending Odometer Reading:\n"))
totalMiles = odoEnd - odoStart

print(rentalCode) # Displays Chosen Rental Code
if rentalCode == 'B' or rentalCode == 'D': # Decides which option has been input and displays the output
  print(daysRented)
else:
  print(weeksRented)

baseCharge = 0
if rentalCode == 'B':
  baseCharge = daysRented * budgetCharge
elif rentalCode == 'D':
  baseCharge = daysRented * dailyCharge
elif rentalCode == 'W':
  baseCharge = weeksRented * weeklyCharge



#Print odoStart, odoEnd and totalMiles
print(odoStart)
print(odoEnd)
print(totalMiles)
# Calculate Charges 2

totalCharge = 0
if rentalCode == 'B':
  totalCharge = baseCharge + (totalMiles * .25)
elif rentalCode == 'D':
  averageDayMiles = int(totalMiles) / int(daysRented)
  if averageDayMiles <= 100:
    totalCharge = baseCharge
  else:
    extraMiles = totalMiles - 100
    totalCharge = baseCharge + (extraMiles * .25)
elif rentalCode == 'W':
  averageWeekMiles = int(totalMiles) / int(weeksRented)
  if averageWeekMiles <= 900:
    totalCharge = baseCharge
  else:
    totalCharge = baseCharge + (weeksRented * 100)

print(totalCharge)

if rentalCode == "W":
    rentalPeriod = weeksRented
else:
    rentalPeriod = daysRented

print(rentalPeriod)

if rentalCode == "B":
    baseCharge = budgetCharge * rentalPeriod
elif rentalCode == "D":
    baseCharge = dailyCharge * rentalPeriod
else:
    baseCharge = weeklyCharge * rentalPeriod




print('Customer Summary')
print('Rental Code:       ' , rentalCode)
print('Rental Period:     ' , rentalPeriod)
print('Starting Odometer: ' , str(odoStart))
print('Ending Odometer:   ' , str(odoEnd))
print('Miles Driven:      ' , str(totalMiles))
print('Amount Due:        $' + '%.2f' % baseCharge)

给你。 daysRented和weeksRented可以取整数。此外，您只能将字符串而不是 int 连接到字符串。另一件事，%.2f 适用于实数而不是字符串。
这是一个示例输出

(B)udget, (D)aily, or (W)eekly rental?
B
Number of Days Rented:2
Starting Odometer Reading:
100
Ending Odometer Reading:
150
B
2
100
150
50
92.5
2
Customer Summary
Rental Code:        B
Rental Period:      2
Starting Odometer:  100
Ending Odometer:    150
Miles Driven:       50
Amount Due:        .00

当我使用“%.2f”时，出现 "a float is required" 错误，为什么？

When I use '%.2f' I get a "a float is required" error, why?

python

decimal

codio