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dynamodb_helpers.py 4.16 KiB
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    import os
    import sys
    
    import configparser
    
    import boto3
    from botocore.exceptions import NoCredentialsError, PartialCredentialsError
    
    from boto3.dynamodb.conditions import Key
    
    import pandas as pd
    from decimal import Decimal
    
    
    from pathlib import Path
    
    
    def get_path_to_data():
        """Return path to data."""
        return Path('Data/')
    
    
    def get_raw_data_path():
        """Return path to raw data."""
        return get_path_to_data() / 'RawData'
    
    
    def get_tidy_data_path():
        """Return path to tidy data."""
        return get_path_to_data() / 'TidyData'
    
    
    
    
    def get_config():
        """
        Reads the configuration file and returns the config object.
        
        Returns:
            config: The config object.
        """
        config = configparser.ConfigParser()
    
        #config_file = os.path.join(os.path.dirname(__file__), 'config.ini')
        #config_file = os.path.abspath(os.path.join(os.getcwd(), 'config.ini'))
        config_file = 'config.ini'
        if not os.path.exists(config_file):
            raise FileNotFoundError(f"The configuration file was not found: {config_file}")
        
        config.read(config_file)
        
        if 'AWS' not in config or 'DYNAMODB' not in config:
            raise KeyError("One or more required sections are missing in the configuration file.")
        
    
        return config
    
    def get_dynamodb_resource():
        """
        Creates a DynamoDB resource using the AWS session.
        
        Returns:
            dynamo_resource: The DynamoDB resource.
        """
        config = get_config()
    
        aws_access_key_id = config['AWS']['aws_access_key_id']
        aws_secret_access_key = config['AWS']['aws_secret_access_key']
        region_name = config['AWS']['region_name']
    
        session = boto3.Session(
            aws_access_key_id=aws_access_key_id,
            aws_secret_access_key=aws_secret_access_key,
            region_name=region_name
        )
        
        dynamo_resource = session.resource('dynamodb')
        return dynamo_resource
    
    
    def list_dynamodb_tables(dynamo_resource):
        """
        Lists all tables in the DynamoDB resource.
        
        Args:
            dynamo_resource: The DynamoDB resource.
        
        Returns:
            list: List of table names.
        """
        tables = [table.name for table in dynamo_resource.tables.all()]
        return tables
    
    def get_movies_table(dynamo_resource):
        """
        Gets the movies table from DynamoDB.
        
        Args:
            dynamo_resource: The DynamoDB resource.
        
        Returns:
            table: The DynamoDB table resource for movies.
        """
        config = get_config()
        table_name = config['DYNAMODB']['table_name']
        return dynamo_resource.Table(table_name)
    
    def get_movie_item(table, year, title):
        """
        Gets a movie item from the DynamoDB table.
        
        Args:
            table: The DynamoDB table resource.
            year: The year of the movie.
            title: The title of the movie.
        
        Returns:
            dict: The movie item.
        """
        response = table.get_item(Key={'year': year, 'title': title})
        return response.get('Item')
    
    def query_movies_by_year(table, year):
        """
        Queries movies by year from the DynamoDB table.
        
        Args:
            table: The DynamoDB table resource.
            year: The year to query.
        
        Returns:
            list: List of movies for the given year.
        """
        response = table.query(
            KeyConditionExpression=Key('year').eq(year)
        )
        return response.get('Items', [])
    
    
    
    def tidy_movie_data(movies):
        """
        Transforms the raw movie data into a tidy DataFrame.
        
        Args:
            movies (list): List of raw movie data.
            
        Returns:
            DataFrame: Tidy DataFrame containing movie data.
        """
        tidy_data = []
        for movie in movies:
            year = movie['year']
            title = movie['title']
            info = movie['info']
            tidy_data.append({
                'year': int(year),
                'title': title,
                'actors': ', '.join(info['actors']),
                'release_date': info['release_date'],
                'plot': info['plot'],
                'genres': ', '.join(info['genres']),
                'image_url': info['image_url'],
                'directors': ', '.join(info['directors']),
                'rating': float(info['rating']),
                'rank': int(info['rank']),
                'running_time_secs': int(info['running_time_secs'])
            })
        
        return pd.DataFrame(tidy_data)