Python raw_input 不会提示

当我运行程序时输入不会提示。我该如何解决？

import sys 
def main(): 
 
    # Initialize list and determine length 
    string_list = raw_input("Enter your strings to be sorted: ").split(' ') 
    string_list.sort() 
    length = len(string_list) 
 
    # If there are more than one strings to sort, print the list 
    # Otherwise break 
    if length > 1:  
        print(string_list) 
    elif length < 0: 
        print("Enter more than one string to sort") 
        return sys.exit() 

请您参考如下方法:

标准习语在这里很有用:

if __name__ == '__main__': 
    main()