我怎样才能让我的for循环从try和except块中停下来的地方继续呢？ Python 3

Question

如果用户未输入数字，我希望程序捕获错误。 如果用户输入字母或只是按“ enter”，则程序将从头开始重新启动for循环。 如何使它从输入错误的地方开始？

#This is the size of the array 
YEAR_SIZE = 12

months = []                     ###This is the array that will hold the rainfall for each month 
monthNames=['January','February','March','April','May',
'June','July','August','September',
'October','November','December']

def getMonthlyRainfall():
  while True:
    try:
      total = 0
      for month in range(YEAR_SIZE):         ###This loop iterates 12 times for 12 entries
         print ("Enter the rainfall for",monthNames[month], "in inches")
         months.append(float(input()))
         continue
    except:
      print ("Try again") 

Answer 1

您可以使用另一个变量来跟踪用户给出的答案：

#This is the size of the array 
YEAR_SIZE = 12

months = []                     ###This is the array that will hold the rainfall for each month 
monthNames=['January','February','March','April','May',
'June','July','August','September',
'October','November','December']


def getMonthlyRainfall():
    ANSWERS = 0

    while True:
        try:
            total = 0
            for month in range(ANSWERS, YEAR_SIZE):         ###This loop iterates 12 times for 12 entries
                print ("Enter the rainfall for",monthNames[month], "in inches")
                x = input()
                months.append(float(x))
                ANSWERS = ANSWERS + 1
        except:
          print ("Try again") 

getMonthlyRainfall()

在这种情况下ANSWERS

Answer 2

在线检查演示

YEAR_SIZE = 12

months = []                     ###This is the array that will hold the rainfall for each month 
monthNames=['January','February','March','April','May',
'June','July','August','September',
'October','November','December']

def getMonthlyRainfall():
  while True:
    total = 0
    for month in range(YEAR_SIZE):         ###This loop iterates 12 times for 12 entries1
       try:

         tmp = get_input(month)
       except ValueError:
         print ("Enter the rainfall for",monthNames[month], "in inches")
         tmp = get_input()
       months.append(tmp)
       continue

def get_input(month):
  try:
    print ("Enter the rainfall for",monthNames[month], "in inches")
    tmp = float(input())
  except ValueError:
    get_input(month)

Answer 3

这是一个更干净的答案：

import calendar

def ask_for_rainfall(month_name):
    while True:
        try:
            return float(input("Enter the rainfall for %s in inches" % month_name))
        except:
            print('Try again')

def get_monthly_rain_fall():
    month_names = list(calendar.month_name[1:])
    return {m_name: ask_for_rainfall(m_name) for m_name in month_names}

# Now you can do
# rain_falls = get_monthly_rain_fall()
# print(rain_falls["January"])