Given

mylist = ['nowplaying', 'PBS', 'PBS', 'nowplaying', 'job', 'debate', 'thenandnow']

get the list of unique items. The output can be one of three ways:

1. Order does not matter.

   ['thenandnow', 'debate', 'nowplaying', 'PBS', 'job']

2. Preserve the order and keep the first unique item.

   ['nowplaying', 'PBS', 'job', 'debate', 'thenandnow']

3. Preserve the order and keep the last unique item.

   ['PBS', 'nowplaying', 'job', 'debate', 'thenandnow']

• Starting from Python 3.7, dictionaries in python are ordered by insertion order. Per https://docs.python.org/3.7/tutorial/datastructures.html#dictionaries

  Performing list(d) on a dictionary returns a list of all the keys used in the dictionary, in insertion order

• Assume Python >= 3.7 is used.

uniq_no_order = list(set(mylist))
print(uniq_no_order)

['nowplaying', 'job', 'debate', 'PBS', 'thenandnow']

uniq_first = list({key:1 for key in mylist}.keys())
print(uniq_first)

['nowplaying', 'PBS', 'job', 'debate', 'thenandnow']

uniq_last = list({key:1 for key in mylist[::-1]}.keys())[::-1]
print(uniq_last)

['PBS', 'nowplaying', 'job', 'debate', 'thenandnow']