9.1 Reading and parsing unstructured data with Bags9.1.1 Selecting and viewing data from a Bag9.1.2 Common parsing issues and how to overcome them9.1.3 Working with delimiters9.2 Transforming, filtering, and folding elements9.2.1 Transforming elements with the map method9.2.2 Filtering Bags with the filter method9.2.3 Calculating descriptive statistics on Bags9.2.4 Creating aggregate functions using the foldby method9.3 Building Arrays and DataFrames from Bags9.4 Using Bags for parallel text analysis with NLTK9.4.1 The basics of bigram analysis9.4.2 Extracting tokens and filtering stopwords9.4.3 Analyzing the bigramsSummary