What are all possible pos tags of NLTK?

Question

How do I find a list with all possible pos tags used by the Natural Language Toolkit (nltk)?

Answer 1

The below can be useful to access a dict keyed by abbreviations:

>>> from nltk.data import load
>>> tagdict = load('help/tagsets/upenn_tagset.pickle')
>>> tagdict['NN'][0]
'noun, common, singular or mass'
>>> tagdict.keys()
['PRP$', 'VBG', 'VBD', '``', 'VBN', ',', "''", 'VBP', 'WDT', ...