Question

我正在写日历程序。如果用户输入年份的负数，则再次要求他们输入正数，直到他们这样做。我如何编写这段代码以允许他们无限次地输入alpabetical字母，直到他们最终在积极的int下？反之亦然？如果他们写了一封信，那么 - 编号然后写信吗？

将输入设置为int现在将允许重复输入字母。但是，如果我把它拿出来，那么我将无法进入int

def func():
    first_year = (input("What year would you like to start?\n"))     #input set to varibale for users desired start yea 

    while type(first_year) == str:
        first_year = int(input("Please enter a number value. What year would you like to start?\n"))

    while first_year < 0:               
        first_year = int(input("Please enter a nonnegative year. What year would you like to start?\n"))        #while loop to make sure year is a valid positive year

    print("You have chosen the year " + str(first_year) + " as your starting year") 

    end_year = int(input("What would you like to print up to?\n"))      #input set to variable for users desired end year

    while end_year < 0:
        end_year = int(input("Please enter a nonnegative year. What year would you like to end with?\n"))

    print("You have chosen the year " + str(end_year) + " as your ending year")   #delete later

    format = input("What date format do you want to print? Ex. with slashes ' 1/1/2000 ' or by printed month 'Januaray, 1, 2000' ? Please enter '-' for slashes or 'print' for printed month." )

Answer 1

input = raw_input("Give a number: ")
try:
    input = int(input)
except ValueError:
    # input is not parsable to string
    do_something()

Answer 2

我会尝试部分解决您的问题。您可以尝试使用isinstance()之类的内容。

def func():
    first_year = (input("What year would you like to start?\n"))     #input set to varibale for users desired start yea 
    if isinstance(first_year,(str,)):   ## checks if first_year is of string type
        ## do whatever you want when its string.
    elif isinstance(first_year,(int,)):  ## checks if first_year is of int type
        ## do what you want when its int.
        if first_year >= 0 : ### this checks for negative value
              # go ahead with your program  
        else:
            ## ask the user to put positive values.

如何在没有崩溃的情况下输入str和int？

2 个答案: