How to make an assert type check upon successful registration if the email is randomly generated?

Question

Python

Good afternoon, I am new to this field, but I would really like comments from experts on this issue. In general, you need to check the text on successful registration
, there is a mail variable that generates random addresses
and there is a line like
verify = driver.find_element_by_class_name("content")
assert verify.text == u"An email with instructions for activating a registered account has been sent to %username%" where
%username% = mail Thanks in advance for your reply.