input: 
  """Given a string, extract all public email addresses from it.
  >>> extract_emails("My email is john@example.com and yours is john@gmail.com")
  ['john@example.com', 'john@gmail.com']
  """
  def extract_emails(text):
      emails = re.findall(r"[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+", text)
      return emails
  
output:     import re