old_contents: import os
  
  from django.conf import settings
  
  
  engines = {
      'sqlite': 'django.db.backends.sqlite3',
      'postgresql': 'django.db.backends.postgresql_psycopg2',
      'mysql': 'django.db.backends.mysql',
  }
  
  
  def config():
      service_name = os.getenv('DATABASE_SERVICE_NAME').upper()
      if service_name:
          engine = engines.get(os.getenv('DATABASE_ENGINE'), engines['sqlite'])
      else:
          engine = engines['sqlite']
      name = os.getenv('DATABASE_NAME')
      if not name and engine == engines['sqlite']:
          name = os.path.join(settings.BASE_DIR, 'db.sqlite3')
      return {
          'ENGINE': engine,
          'NAME': name,
          'USER': os.getenv('DATABASE_USER'),
          'PASSWORD': os.getenv('DATABASE_PASSWORD'),
          'HOST': os.getenv('{}_SERVICE_HOST'.format(service_name)),
          'PORT': os.getenv('{}_SERVICE_PORT'.format(service_name)),
      }
  
new_contents: import os
  
  from django.conf import settings
  
  
  engines = {
      'sqlite': 'django.db.backends.sqlite3',
      'postgresql': 'django.db.backends.postgresql_psycopg2',
      'mysql': 'django.db.backends.mysql',
  }
  
  
  def config():
      service_name = os.getenv('DATABASE_SERVICE_NAME', '').upper()
      if service_name:
          engine = engines.get(os.getenv('DATABASE_ENGINE'), engines['sqlite'])
      else:
          engine = engines['sqlite']
      name = os.getenv('DATABASE_NAME')
      if not name and engine == engines['sqlite']:
          name = os.path.join(settings.BASE_DIR, 'db.sqlite3')
      return {
          'ENGINE': engine,
          'NAME': name,
          'USER': os.getenv('DATABASE_USER'),
          'PASSWORD': os.getenv('DATABASE_PASSWORD'),
          'HOST': os.getenv('{}_SERVICE_HOST'.format(service_name)),
          'PORT': os.getenv('{}_SERVICE_PORT'.format(service_name)),
      }
  
subject: Fix type error