英文:
why get(key, value) returns the correct value even if you type in the wrong value into the value spot?
问题
我知道这个方法是做什么的，但我试图理解它为什么这样做。例如：
dic = {'a': 500, 'b': 600}
dic.get('a', 5)
#输出
500
我本来以为这会是无效的，但它似乎只是打印出了正确的值，而不是我输入的错误值。为什么会这样，或者是我漏掉了什么其他的东西？谢谢！
英文:
so I know what this method does, but i am trying to understand why it does this. For example:
dic = {'a':500, 'b':600}
dic.get('a', 5)
#output
500
i would expect this to be invalid. but it seems to just print the correct value instead of the incorrect value i typed. why does this do that, or is there something else happening that i am missing. Thanks!
答案1
得分: 1
如果您阅读dict.get的文档，您将看到第二个参数是在字典中不存在键时返回的。
例如：
my_dict = {"a": 100, "b": 200}
print(my_dict.get("a", 200)) # 100
print(my_dict.get("c", 300)) # 300
print(my_dict["c"]) # 引发KeyError
英文:
If you read the docs for dict.get you will see that the second argument is meant to be returned if there is no key present in the dictionary.
For example:
my_dict = {"a": 100, "b": 200}
print(my_dict.get("a", 200)) # 100
print(my_dict.get("c", 300)) # 300
print(my_dict["c"]) # raised KeyError
答案2
得分: 0
dict.get()接受一个键和一个可选的值参数，如果未找到键，则返回该值，不与键的值进行比较。我不知道为什么你_会_想这样使用它，但你可以使用这个来获取你的结果：
dic = {'a': 500, 'b': 600}
key, value = 'a', 5
result = dic.get(key)
if result is None or result != value:
print("Key value pair not found.")
英文:
dict.get() takes a key and optional value parameter, which is returned if the key is not found and does not compare it to the value of the key. I don't know why you would want to use it like that, but you could use this to get your result:
dic = {'a': 500, 'b': 600}
key, value = 'a', 5
result = dic.get(key)
if result is None or result != value:
print("Key value pair not found.")
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