brock@montreat:~/csci431/webpage/notes$ python3
Python 3.6.7 (default, Oct 22 2018, 11:32:17) 
[GCC 8.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from itertools import groupby
>>> things = [("animal", "bear"), ("animal", "duck"), ("plant", "cactus"), ("vehicle", "speed boat"), ("vehicle", "school bus")]
>>> magic = groupby(things, lambda x: x[0])
>>> for x in magic:
...     print(x[0])
...     for y in x[1]:
...         print("  {0}".format(y[1]))
... 
animal
  bear
  duck
plant
  cactus
vehicle
  speed boat
  school bus
>>>