Specifying Keys in txt file Dictionary

[catsrule]

So I am trying to build a dictionary that maps the key value to a specific value in a txt file. Its a txt file about movie reviews and I am trying to separate it into random reviews by each author. The format of the text file is |reviewId userId itemId rating title content|. So how would I specify that I want 100 random reviews from each author (userID) and place each all the random reviews into separate text files for test/train data.

[Larz60+]

use a dictionary:

    'Gone With the Wind': {
        'stars': {
            'Vivien Leigh': 'Scarlett O'Hara',
            'William Clark Gable': 'Rhett Butler',
            ...
        },
        'other stuff': {
        }
    }