There are many ways to merge Python dictionaries. I’m going to show just two of the most common ways.

Merge and Join #

The first way will merge the two dictionaries, but alters the first. This obviously requires fewer objects in memory.

dict1.update(dict2)

Merge and Create New #

This will merge python dictionaries without changing either one. This is useful when you want to preserve the contents of both and create a 3rd.

def merge_dict(dict1, dict2):
    """
    Merge the contents of two dictionaries together and create a 3rd
    dictionary. Items in dict1 with the same name as items in dict2
    will be overridden. i.e. dict2 wins.
    
    Args:
        dict1: First dictionary of items
        dict2: Second dictionary of items. This one wins in the
            situation where both dictionaries have the same key name.
    
    Returns:
        Combined dictionary
    """
    # This works by expanding each dict into (key, value) pairs
    merged = {**dict1, **dict2}
    return merged