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

[Cameron Simpson]

On 28Dec2020 13:08, Mats Wichmann <mats at wichmann.us> 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.

Others have pointed out: '@' in s

>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 is a functional email address is hard, involves 
delivering email and then finding out if it was delivered.

A proper syntax check requires parsing an RFC5322 address grammar:

    https://tools.ietf.org/rfcmarkup/5322#section-3.4

Fortunately, Python ships with one of those in the email.utils module.

The parseaddr() function will parse a single address, and getaddresses() 
will parse a list of addresses such as might be in a To: header line.

They work well - I've been filing my email based on these for years - 
MANY thousands of messages.

Cheers,
Cameron Simpson <cs at cskk.id.au>