# -*- coding: utf-8 -*-
"""
Created on Fri Mar 22 20:00:53 2019

@author: Matth
"""

import re
def urgent_emails(emails):

    urgentRegex = re.compile('urgent')
    list = []

    ## loop through every email in email list
    for i in emails:

        ## construct variable that has string "urgent" if value belonging to key 'subject' contains UrGent
       variable = urgentRegex.search(
               (i['subject']).lower())

       ## check if variable is equal to urgent
       if variable.group()=='urgent':
           list.append(i['author'])
    return list

emails1 = [
    {
        'author': 'emil@booking.com',
        'subject': 'Urgent: you better do your homework!',
        'content': 'New session is coming, please get the homework ready so we can do amazing stuff!'
    },
    {
        'author': 'kerem@booking.com',
        'subject': 'News',
        'content': 'I am going to take over Emil\'s class next week. Be sure to be there!'
    },
    {
        'author': 'staff@booking.com',
        'subject': 'URGENT - change your password now!',
        'content': 'Your password has expired, change your password now!!!'
    },
    {
        'author': 'workbook@booking.com',
        'subject': '[EXTERNAL]Whatever news have been posted...',
        'content': 'X has done Y Urgent thing on platform Z, hooray!'
    }
]

urgent_emails(emails1)