Splendid NLP Librabry

TextBlob -- a simplified solution based on NLTK. Well, not so flexible but that's the price of any simplification. To name some of its features that caught my attention at first glance:
from textblob import TextBlob

# POS Tagging
TextBlob("TextBlob aims to provide access
  to common text-processing operations through a familiar interface.").tags

"""
[(u'TextBlob', u'NNP'),
 (u'aims', u'VBZ'),
 (u'to', u'TO'),
 (u'provide', u'VB'),
 (u'access', u'NN'),
 (u'to', u'TO'),
 (u'common', u'VB'),
 (u'text-processing', u'JJ'),
 (u'operations', u'NNS'),
 (u'through', u'IN'),
 (u'a', u'DT'),
 (u'familiar', u'JJ'),
 (u'interface', u'NN')]
"""

# Sentiment Analysis
TextBlob("I like TextBlob a lot. It is a great library!").sentiment
"""
(1.0, 0.75)
"""

# SynSets Operations (WordNet Integration)
money = Synset('money.n.01')
entertainment = Synset('entertainment.n.01')
money.path_similarity(entertainment)
"""
0.08333333333333333
"""

# Translation and Language Detection (Google Translate API)
TextBlob("TextBlob aims to provide access
  to common text-processing operations through a familiar interface.").translate(to="bg")
"""
TextBlob("TextBlob има за цел да осигури достъп
  до общи операции за обработка на текст чрез познатия интерфейс.")
"""

# Spelling Correction
TextBlob("I havv gooodd speeling!").correct()
"""
I have good spelling!
"""
As for the classification -- yes it's here too. However, I would recommend Jacob Perkins nltk trainer CLI tools when it comes to classification.