machine-learning/notebook.ipynb

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    "# Machine Learning project in SoSe 2025 at HTW Saar\n",
    "## Idea\n",
    "The goal of this project is predicting the genre(s) of a game/bundle through its given description(s)\n",
    "\n",
    "## Dataset\n",
    "For our project we use a Steam Dataset provided on moodle, since it has all information we plan on using.\n",
    "The Dataset has been cut to only 2000 data points to be runnable on weaker devices."
   ]
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   "source": [
    "import numpy as np\n",
    "import pandas as pd\n",
    "from sklearn import set_config\n",
    "\n",
    "set_config(transform_output=\"pandas\")\n",
    "\n",
    "dataset = pd.read_csv(\"./games_march2025_cleaned_2k.csv\",sep=\",\")\n",
    "print(dataset.head())"
   ],
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    "## Preparation of the Dataset\n",
    "### Removing Uniques\n",
    "We would remove the following features from the Training-Set as they can/could uniquely identify a datapoint, but we don't as they will be removed in the next step anyway\n",
    "- AppId\n",
    "- Name of the Game\n",
    "- Realease Date\n",
    "- Reviews\n",
    "- Header Image\n",
    "- Website\n",
    "- Support URL\n",
    "- Support Email\n",
    "- MetaCritic URL\n",
    "- Developer\n",
    "- Publisher\n",
    "- Screenshots\n",
    "- Movies\n",
    "- Estimated Owners"
   ]
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   "source": [
    "#dataset.drop(['appid', 'name', 'release_date', 'reviews', 'header_image', 'website', 'support_url', 'support_email', 'metacritic_url', 'notes', 'developers', 'publishers', 'screenshots', 'movies', 'estimated_owners'], axis=1, inplace=True)\n",
    "#print(dataset.head())"
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   "source": [
    "## Hold onto necessary information\n",
    "Our model should turn a textual description of a game into its genre. For that we need all the textual information a game has, as well as the genres of the game.\n",
    "We use a ColumnTransformer to drop all unnecessary lines, merge all descriptions of a game into one big description and hold onto the genres\n",
    "\n",
    "It is important to use ``verbose_feature_names_out=False`` so the feature names don't get changed"
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   "source": [
    "from sklearn.compose import ColumnTransformer\n",
    "from sklearn.preprocessing import FunctionTransformer\n",
    "\n",
    "# desc, genres\n",
    "column_transformer = ColumnTransformer([\n",
    "        # merge all descriptions\n",
    "        ('desc', FunctionTransformer(lambda X: X.fillna('').agg(' '.join, axis=1).to_frame(name=\"desc\")),\n",
    "            ['detailed_description', 'about_the_game', 'short_description']),\n",
    "        ('pass', 'passthrough', ['genres']),\n",
    "    ],\n",
    "    verbose_feature_names_out=False\n",
    ")\n",
    "dataset = column_transformer.fit_transform(dataset)\n",
    "print(dataset.head())"
   ],
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   "source": [
    "### Adding missing Information\n",
    "Some Games might not have any descriptions. For these we Input an Empty String\n",
    "**TODO: check if dropna and fillna numeric_only is needed, as we dont have any numbers**"
   ],
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   "source": [
    "# missing numeric values => mean\n",
    "dataset.fillna(dataset.mean(numeric_only=True), inplace=True)\n",
    "# missing strings => empty string?\n",
    "dataset.fillna('', inplace=True)\n",
    "# drop all lines with missing values\n",
    "dataset.dropna(inplace=True)"
   ],
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   "source": [
    "## Transform Genres\n",
    "The genre information currently is a string holding a python array of genres. While this is machine-readable, we need One-Hot-Encoding for our model to work.\n",
    "\n",
    "#### Serializing the String-Array\n",
    "The \"ast\" library can interpret python strings as python code, and as such will be used for serializing the genres."
   ],
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   "source": [
    "import ast\n",
    "\n",
    "dataset['genres'] = dataset['genres'].map(lambda s: ast.literal_eval(s))\n",
    "print(dataset['genres'])"
   ],
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    "#### One-Hot-Encoding an Python-Array\n",
    "The sklearn ``OneHotEncoder()`` is only able to work with an 1D Array of different classes, such as ``['Politics', 'Sport', 'Culture']``. Every datapoint can only have one concurrent classification.\n",
    "Steam allows an app/bundle to have multiple genres. As such, our dataset has an 2D Array of different classes, which sklearn's ``MultiLabelBinarizer()`` does support."
   ],
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   "metadata": {},
   "cell_type": "code",
   "source": [
    "from sklearn.preprocessing import MultiLabelBinarizer\n",
    "\n",
    "mlb_genres = MultiLabelBinarizer()\n",
    "genres_encoded = mlb_genres.fit_transform(dataset.pop('genres'))\n",
    "genres_df = pd.DataFrame(genres_encoded, columns=mlb_genres.classes_)\n",
    "print(genres_df.head())"
   ],
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   "outputs": [],
   "execution_count": null
  },
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   "cell_type": "markdown",
   "source": "With this, our target matrix is completed.",
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   "source": [
    "### Structurizing Text\n",
    "If we want our Model to be able to use text as an input, we have to vectorize the text. TF-IDF (Inverse Document Frequency) is an easy way of transforming each word into a feature with a 0 to 1 value. **TODO: filter out stopwords**"
   ]
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  {
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   "source": [
    "from sklearn.feature_extraction.text import TfidfVectorizer\n",
    "\n",
    "vectorizer = TfidfVectorizer()\n",
    "tfidf_matrix = vectorizer.fit_transform(dataset['desc']) # matrix, not pandas df\n",
    "tfidf_df = pd.DataFrame(tfidf_matrix.toarray(), columns=vectorizer.get_feature_names_out())\n",
    "print(tfidf_df.head())"
   ],
   "outputs": [],
   "execution_count": null
  },
  {
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   "metadata": {},
   "source": "With this our feature matrix is completed"
  },
  {
   "metadata": {},
   "cell_type": "code",
   "outputs": [],
   "execution_count": null,
   "source": [
    "X = tfidf_df\n",
    "y = genres_df"
   ],
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   "source": [
    "## The Model\n",
    "\n",
    "####  Removing unpredicatble Datapoints\n",
    "Some Datapoints don't have a genre assigned (all feature values in y are 0). The model we use can't handle such cases, thus they have to be removed.\n",
    "We filter after all values that we can use with a mask, and apply that mask to our matrices."
   ],
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   "source": [
    "mask = y.sum(axis=1).map(lambda x: x > 0)\n",
    "print((mask == False).sum()) # count of unpredictable datapoints\n",
    "\n",
    "X_clean = X[mask]\n",
    "y_clean = y[mask]"
   ],
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  {
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   "id": "091d7e13",
   "metadata": {},
   "source": [
    "# Splitting up data\n",
    "We have to split up our data into training and testing data.\n",
    "Using random_state=0 guarantees reproducability."
   ]
  },
  {
   "cell_type": "code",
   "id": "cfbf3787",
   "metadata": {
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   "source": [
    "from sklearn.model_selection import train_test_split\n",
    "\n",
    "X_train, X_test, y_train, y_test = train_test_split(X_clean, y_clean, random_state=0)"
   ],
   "outputs": [],
   "execution_count": null
  },
  {
   "cell_type": "markdown",
   "id": "12b5283d",
   "metadata": {},
   "source": [
    "# Model Selection\n",
    "**TODO Deciding which model to use for this task**\n",
    "\n",
    "As a game can have multiple genres, our Model(s) has to be capable of multi-label-classification. sklearn's ``MultiOutputClassifier`` can do this. As a backend for ``MultiOutputClassifier`` we use ``LogisticRegression``"
   ]
  },
  {
   "metadata": {},
   "cell_type": "code",
   "outputs": [],
   "execution_count": null,
   "source": [
    "# n_jobs=1 since there seems to be some multithreading join issue in sklearn (or my pc is too bad)\n",
    "multi_target_clf = MultiOutputClassifier(LogisticRegression(max_iter=1337, random_state=0), n_jobs=1)\n",
    "\n",
    "multi_target_clf.fit(X_train, y_train)\n",
    "\n",
    "y_pred = multi_target_clf.predict(X_test)"
   ],
   "id": "8c1d72c4532bd509"
  },
  {
   "cell_type": "markdown",
   "id": "0faa9856",
   "metadata": {},
   "source": [
    "# Evaluation\n",
    "**TODO Test the Model with the test data**"
   ]
  },
  {
   "metadata": {},
   "cell_type": "code",
   "outputs": [],
   "execution_count": null,
   "source": "print(classification_report(y_test, y_pred, zero_division=0.0))",
   "id": "e2ebea6945193e07"
  },
  {
   "cell_type": "markdown",
   "id": "2aeb6fc2",
   "metadata": {},
   "source": [
    "# Optimization\n",
    "**TODO optimize the model based on the test results**"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "79b20645",
   "metadata": {},
   "source": [
    "# Validation\n",
    "**TODO Predict actual values**"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "3b709fb7",
   "metadata": {},
   "source": [
    "# Conclusion and outlook\n",
    "**TODO Write a conclusion and outlook what can be done and where the issues were.**"
   ]
  }
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