Which method to check if string index is queal to character.

[Richard Damon]

On 12/28/20 3:08 PM, Mats Wichmann wrote:
> On 12/28/20 10:46 AM, Marco Sulla wrote:
>> On Mon, 28 Dec 2020 at 17:37, Bischoop <Bischoop at vimart.net> wrote:
>>>
>>> I'd like to check if there's "@" in a string and wondering if any
>>> method
>>> is better/safer than others. I was told on one occasion that I should
>>> use is than ==, so how would be on this example.
>>>
>>> s = 'this at mail.is'
>>
>> You could do simply
>>
>> if "@" in s:
>>
>> but probably what you really want is a regular expression.
>>
>
> Will add that Yes, you should always validate your inputs, but No, the
> presence of an @ sign in a text string is not sufficient to know it's
> a valid email address. Unfortunately validating that is hard.
>
Validating that it meets the SYNTAX of an email address isn't THAT hard,
but there are a number of edge cases to worry about.

Validating that it is a working email address (presumably after
verifying that it has a proper syntax) is much harder, and basically
requires trying to send to the address, and to really confirm that it is
good requires them to do something actively with a message you send
them. And then nothing says the address will continue to be valid.

-- 
Richard Damon