Python 用户如何在不崩溃的情况下同时输入str和int？

我正在写一个日历程序。如果用户输入年份的负数，它会再次要求用户输入正数，直到用户输入负数为止。我如何编写代码，允许他们错误地输入任意数量的字母，直到最后输入正整数？反之亦然？如果他们写一封信，那么-数字，然后是字母

将输入设置为int将允许重复输入字母。但是如果我把它拿出来，我就永远不能插入一个int

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我将设法部分解决你的问题。您可以尝试使用类似这样的isinstance

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.      

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

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.