检查列表中的项目是否存在

Question

I have list of UUIDs (block_list) and want to check if one specific UUID is listed in that list.

list(block_list)

Out[41]: 
[ ('f779e98c-a541-4ae2-afcb-b0da2e5bee24',),
 ('a005bc7b-c06d-48bf-8259-757d52c70330',),
 ('8af278b1-089e-40e9-a57d-856efe336c26',)]

Why is that giving me a false?

'8af278b1-089e-40e9-a57d-856efe336c26' in block_list Answer: False

Thanks Robert

Answer 1

因为 '8af278b1-089e-40e9-a57d-856efe336c26' 是一个字符串，但您的列表由元组组成

Answer 2

The reason it is false because you are checking if a string is in a list. But your list is a list of the tuples. So you have to check if any particular tuple is in the list.

So instead you need following codes:

('8af278b1-089e-40e9-a57d-856efe336c26') in block_list

Now the output will be True

Answer 3

You should pass a string inside a tuple, do not pass the raw string to see if it's in the list. Here is a simple function that can do it for you by passing a raw string and nesting it inside a tuple with a trailing comma:

def check_string(string):
    if ((string, ) in my_list):
        return True
    else:
        return False