Can I use an if statement to check that a value is in a dictionary list?
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我想让用户使用输入从字典中调用变量,但我想使用一种方法来检查该值是否存在。
例子:
1 2 3 4 5 6 7 | dictionary = {'a': 1, 'b': 2, 'c': 3} chosen = raw_input("choose one:") if(dictionary[chosen] == true): print(chosen) else: print("Invalid choice") |
当我运行类似这样的程序时,总是默认使用
如果清除语法错误并使用
1 2 3 4 5 6 7 8 | dictionary = {'a': 1, 'b': 2, 'c': 3} chosen = raw_input("choose one:") if chosen in dictionary: #added colon and changed to if chosen in dictionary print(chosen +" :" + str(dictionary[chosen])) #changed to bring both key and value because I didn't know which you wanted else: print("Invalid choice") #I added a new line. |