In python use the file 100-0.txt which is the complete works of Shakespeare. By word we will refer to the elements of a list that is produced by splitting the string containing the contents of the file on whitespace. You will need to remove punctuation and convert all words to lowercase.

Create a dictionary which contains the frequencies for the bigrams in the file. A bigram is a pair of words which occur one after the other. Bigrams should occur within a sentence so you may need to first create a list of sentences. You can assume that splitting on . will accomplish this although that is unlikely to be the case as . can appear in different contexts.