An inverted index is a mapping of words to their location in a set of documents. Most modern search engines utilize some form of an inverted index to process user-submitted queries.

The goal is to build an inverted index that supports the queries. This means that you will need a positional inverted index that maps a word to locations in a set of documents.

Use Python to build an inverted index:

The inverted index should have these characteristics:

-No punctuation, numbers, or symbols should be represented in the index.

-These stopwords should not be included in the index: and, but, is, the, to. You may use any method you want to support this.

-All words in the index should be converted to lower case.

Your program should assume a set of files. You may assume that all of these files are in a directory. Although stopwords are not be used in the index, it should not affect the position of the other words. For example, assume that your file consists of the words The beauty and the beast. The word Beauty is at position 2 and the word beast is at position 5.