T1

def dicts_union_preserve(first_dict, second_dict):
    """
    Function that takes in two dictionaries as arguments, and returns a new dictionary that contains all key-value pairs from both input dictionaries.
    If a key already exists in the first dictionary, its value will be preserved in a list with the value from the second dictionary.

    Args:
    first_dict (dict): The first dictionary to be merged
    second_dict (dict): The second dictionary to be merged

    Returns:
    dict: A new dictionary containing all key-value pairs from both input dictionaries

    Example:
    first_dict = {'Steven': 25, 'Jack': 21, 'Alice': 31, 'John': 41}
    second_dict = {'Steven': 31, 'Jack': 17, 'Bob': 33}
    new_dict = dicts_union_preserve(first_dict, second_dict)
    # new_dict: {'Steven': [25, 31], 'Jack': [21, 17], 'Alice': [31], 'John': [41], 'Bob': [33]}

    """
    # Create a new dictionary to store the union of key-value pairs
    union_dict = {}

    # Iterate through the key-value pairs in the first dictionary
    for key, value in first_dict.items():
        # Check if the key already exists in the union dictionary
        if key in union_dict:
            # If the key already exists, preserve the value in a list
            union_dict[key].append(value)
        else:
            # If the key does not exist, add the key-value pair to the union dictionary
            union_dict[key] = [value]

    # Iterate through the key-value pairs in the second dictionary
    for key, value in second_dict.items():
        # Check if the key already exists in the union dictionary
        if key in union_dict:
            # If the key already exists, preserve the value in a list
            union_dict[key].append(value)
        else:
            # If the key does not exist, add the key-value pair to the union dictionary
            union_dict[key] = [value]

    # Return the union dictionary
    return union_dict


#This function iterates through the key-value pairs in both input dictionaries, adding the key-value pairs to the union dictionary.
#It checks if the key already exists in the union dictionary, if it does it preserves the value in a list, if not it creates a new key #with the value in a list.

#first_dict = {'Steven': 25, 'Jack': 21, 'Alice': 31, 'John': 41}
#second_dict = {'Steven': 31, 'Jack': 17, 'Bob': 33}
#new_dict = dicts_union_preserve(first_dict, second_dict)
#print(new_dict)