# variable.find() searches for the position of one string within another. Values printed are the index of the substring. Outputs are in comment. 
data = 'From stephen.marquard@uct.ac.za Sat Jan  5 09:14:16 2008'
atpos = data.find('@')
print(atpos)
# 21
sppos = data.find(' ',atpos)
print(sppos)
# 31
host = data[atpos+1:sppos]
print(host)
# uct.ac.za