Please provide a brief summay of this code.

Fill missing values

listings.fillna$(\{\text{'}$bathrooms$\text{'}$: listings$[\text{'}$bathrooms$\text{'}].$median$(),$'review$\_$scores$\_$rating': listings$[\text{'}$review$\_$scores$\_$rating'$].$median$(),\},$ inplace$==$True$)$listings$[\text{'}$room$\_$type'$]=$ listings$[\text{'}$room$\_$type'$].$astype$(\text{'}$category$\text{'})$

listings$[\text{'}$property$\_$type'$]=$ listings$[\text{'}$property$\_$type'$].$astype$(\text{'}$category$\text{'})$

listings$[\text{'}$neighbourhood$\_$cleansed'$]=$ listings$[\text{'}$neighbourhood$\_$cleansed'$].$astype$(\text{'}$category$\text{'})$