computer_parts = {
  'hdd': [
    'WD',
    'kingston'
  ],
  'ram': [
    'corsair',
    'hyperx'
  ]
}

def find_part(part_type, part_name):
  try:
    available_parts = computer_parts[part_type]
    for part in available_parts:
      if part_name in part:
        return part
    # nie znaleziono podzespołu
    return None
  except KeyError:
    # zły typ podzespołu
    return None

print(find_part('ram', 'hyper'))