A Naive Bayesian Classifier. The Classifier class can be trained by "classifier.train(True,'I am so happy!')" or "classifier.train(False,'I am a sad man. ')". To check if something falls in either the True or the False category.

Classify.py

#! /usr/bin/python2                                                                                                                                                                                               

from __future__ import division

from ignoreWords import *

class Classifier:
  def __init__ (self):
    self.examples = []
  
  def classify (self, message):
    if self.examples != []:
      return self.chanceOfCategory(True, message) > self.chanceOfCategory(False, message)
    else: print("You need to give examples before a classification can occur! ")

  def chanceOfCategory (self, category, message):
    cleanMessage    = self.zoneInOnCategory(category, self.cleanMessage(message) )
    examples        = self.getExamples()
    examplesLen     = len (examples)
    categoryExamples    = self.getExamples(category=category)
    categoryExamplesLen = len (categoryExamples)

    probOfCategory = categoryExamplesLen / examplesLen
    probOfWords = 1
    for word in cleanMessage:
      # Numerator
      examplesWithWord = 0
      for example in categoryExamples:
        if word in example:
          examplesWithWord += 1
      if examplesWithWord > 0: probOfCategory *= examplesWithWord / categoryExamplesLen
      # Denominator
      examplesWithWord = 0
      for example in examples:
        if word in example: examplesWithWord += 1
      if examplesWithWord > 0: probOfWords *= examplesWithWord / examplesLen 

    probOfCategoryGivenWords = probOfCategory / probOfWords

    return probOfCategoryGivenWords

  def cleanMessage(self, message):
    newMessage = []
    for word in message.strip().replace(".","").replace(",","").replace("?","").replace("!","").split(" "):
      if not word.lower() in ignoreWords: newMessage.append(word.lower())
    return newMessage

  def zoneInOnCategory(self, category, cleanMessage):
    newMessage = []
    categoryExamples = [item for sublist in self.getExamples(category=category) for item in sublist]
    for word in cleanMessage:
      if word in categoryExamples: newMessage.append(word)
    return newMessage

  def getExamples(self, category = None):
    if category == None: return map (lambda example: example[1] ,self.examples)
    else: return map (lambda example: example[1], filter (lambda example: example[0] == category, self.examples) )

  def train(self, category, message):
    self.examples.append( (category, self.cleanMessage(message) ) )

ignoreWords.py

ignoreWords = [                                                                                                                                                                                                   
    'a', 'about', 'above', 'across', 'after', 'afterwards',
    'again', 'against', 'all', 'almost', 'alone', 'along',
    'already', 'also', 'although', 'always', 'am', 'among',
    'amongst', 'amoungst', 'amount', 'an', 'and', 'another',
    'any', 'anyhow', 'anyone', 'anything', 'anyway', 'anywhere',
    'are', 'around', 'as', 'at', 'back', 'be',
    'became', 'because', 'become', 'becomes', 'becoming', 'been',
    'before', 'beforehand', 'behind', 'being', 'below', 'beside',
    'besides', 'between', 'beyond', 'bill', 'both', 'bottom',
    'but', 'by', 'call', 'can', 'cannot', 'cant', 'dont',
    'co', 'computer', 'con', 'could', 'couldnt', 'cry',
    'de', 'describe', 'detail', 'do', 'done', 'down',
    'due', 'during', 'each', 'eg', 'eight', 'either',
    'eleven', 'else', 'elsewhere', 'empty', 'enough', 'etc', 'even', 'ever', 'every',
    'everyone', 'everything', 'everywhere', 'except', 'few', 'fifteen',
    'fify', 'fill', 'find', 'fire', 'first', 'five',
    'for', 'former', 'formerly', 'forty', 'found', 'four',
    'from', 'front', 'full', 'further', 'get', 'give',
    'go', 'had', 'has', 'hasnt', 'have', 'he',
    'hence', 'her', 'here', 'hereafter', 'hereby', 'herein',
    'hereupon', 'hers', 'herself', 'him', 'himself', 'his',
    'how', 'however', 'hundred', 'i', 'ie', 'if',
    'in', 'inc', 'indeed', 'interest', 'into', 'is',
    'it', 'its', 'itself', 'keep', 'last', 'latter',
    'latterly', 'least', 'less', 'ltd', 'made', 'many',
    'may', 'me', 'meanwhile', 'might', 'mill', 'mine',
    'more', 'moreover', 'most', 'mostly', 'move', 'much',
    'must', 'my', 'myself', 'name', 'namely', 'neither',
    'never', 'nevertheless', 'next', 'nine', 'no', 'nobody',
    'none', 'noone', 'nor', 'not', 'nothing', 'now',
    'nowhere', 'of', 'off', 'often', 'on', 'once',
    'one', 'only', 'onto', 'or', 'other', 'others',
    'otherwise', 'our', 'ours', 'ourselves', 'out', 'over',
    'own', 'part', 'per', 'perhaps', 'please', 'put',
    'rather', 're', 'same', 'see', 'seem', 'seemed',
    'seeming', 'seems', 'serious', 'several', 'she', 'should',
    'show', 'side', 'since', 'sincere', 'six', 'sixty',
    'so', 'some', 'somehow', 'someone', 'something', 'sometime',
    'sometimes', 'somewhere', 'still', 'such', 'system', 'take',
    'ten', 'than', 'that', 'the', 'their', 'them',
    'themselves', 'then', 'thence', 'there', 'thereafter', 'thereby',
    'therefore', 'therein', 'thereupon', 'these', 'they', 'thick',
    'thin', 'third', 'this', 'those', 'though', 'three',
    'through', 'throughout', 'thru', 'thus', 'to', 'together',
    'too', 'top', 'toward', 'towards', 'twelve', 'twenty',
    'two', 'un', 'under', 'until', 'up', 'upon',
    'us', 'very', 'via', 'was', 'we', 'well',
    'were', 'what', 'whatever', 'when', 'whence', 'whenever',
    'where', 'whereafter', 'whereas', 'whereby', 'wherein', 'whereupon',
    'wherever', 'whether', 'which', 'while', 'whither', 'who',
    'whoever', 'whole', 'whom', 'whose', 'why', 'will',
    'with', 'within', 'without', 'would', 'yet', 'you', 'your', 'yours',
    'yourself', 'yourselves'
]