Predicting movie genres with PyMongo and Doc2Vec.

Utilising:

• GenSim models.doc2vec
• PyMongo

Tested with :

• Python v3.9
• PyMongo v4.1.1
• MongoDB v5.0
• GenSim v4.1

Data

A very small set of data is provided with this repository for example purposes. There are two json files that are ready to import into a MongoDB deployment.

• Small set of data for training the model: data/training.json
• Small set of data for testing the output model: data/test.json

To import the files into MongoDB you can use mongoimport:

mongoimport --db topics --collection movies --file ./data/training.json
mongoimport --db topics --collection test --file ./data/test.json 

Custom Data

Essentially you need a MongoDB collection with document structure as below example:

{
  "_id": ObjectId("57ff3452b62f007fe3d033b9"),
  "Title": "Circle",
  "Plot": "In a massive, mysterious chamber, fifty strangers awaken to find themselves ...",
  "Actors": "Michael Nardelli, Allegra Masters, Molly Jackson, Jordi Vilasuso",
  "Year": "2015",
  "Genre": "Drama, Horror, Mystery",  
  "Language": "English",
  ...
}

You can either construct the document yourself, or fetch existing information from movies' sites.

The example data was collected by fetching movies data from : MovieLens Latest Datasets. There's a file called ./ml-latest-small/links.csv that contains movieId. This ID can be used to fetch the related movie information from omdbapi.com. You would need to register and activate an API key. The site provides 1000 API calls per day for free.

Use build_dataset.py script as an example to fetch more movies data from omdbapi.com. The script will output a json file that could be imported to MongoDB using mongoimport.

Building a Model

The prediction model utilises movie's Title, Plot and Actors fields. You can create a doc2vec model file using modeller.py command line. See modeller.py --help for more information. Below is an example command to read from database topics and collection movies to create a model file called example.model:

./modeller.py --db topics --coll movies --model example.model

Use the Model

Provide the generated doc2vec model file as input to analyser.py to predict the genres of movie(s). See analyser.py --help for more information. Below is an example command to read documents from database topics and collection test and predict the genres using example.model:

./analyser.py --db topics --coll test --limit 3 --model example.model

Output example:

INFO : Title: Terminator Genisys
INFO : Plots: When John Connor (Jason Clarke), leader of the human resistance, sends Sgt. Kyle Reese (Jai Courtney) back to 1984 to protect Sarah Connor (Emilia Clarke) and safeguard the future, an unexpected turn of events creates a fractured timeline. Now, Sgt. Reese finds himself in a new and unfamiliar version of the past, where he is faced with unlikely allies, including the Guardian (Arnold Schwarzenegger), dangerous new enemies, and an unexpected new mission: To reset the future...
INFO : Actual Genres: [u'Action', u'Adventure', u'Sci-Fi']
INFO : precomputing L2-norms of doc weight vectors
INFO : Most similar:  [(u'Adventure', 0.5624773502349854), (u'Action', 0.5235205292701721), (u'Animation', 0.5159382820129395)]
INFO :