Python: Extract the first name from an email address using if-else statements. def extract_name(s): """ Returns the first name of the person in e-mail address s. We assume (see the precondition below) that the e-mail address is in one of two forms: last.first@megacorp.com first.last@mompop.net where first and last correspond to the person's first and last name. Names are not empty, and contain only letters. Everything after the @ is guaranteed to be exactly as shown. The function preserves the capitalization of the e-mail address. Examples: extract_name('smith.john@megacorp.com') returns 'john' extract_name('maggie.white@mompop.net') returns 'maggie' extract_name('Bob.Bird@mompop.net') returns 'Bob' Parameter s: The e-mail address to extract from Precondition: s is in one of the two address formats described above """ # You must use an if-else statement in this function.