a better way to code this to fix a URL?

[DeaD_EyE]

If the url should always start with https even, if only a hostname is given, you could use this:

from urllib.parse import urlsplit, urlunsplit


def conv2(url):
    return urlunsplit(("https", *urlsplit(url)[1:]))

But I would prefer an error message, that this scheme is not supported or that the url is mistyped.
Automatic correction of human input, leads to funny outcomes.

And sometimes gene sequences are also renamed because Excel has interpreted the text input and turned the name into a date.