How to append a dictionary value to an existing dictionary value?

Question

Let's say I have a:

dict = {"Main": ["Tammy","Elisha","Julius"],
        "Elisha": ["Kenneth"]
       }

The context is like a Queue system. The Main is the normal queue. While "Elisha:[Kenneth]" is like a Cut queue. You can imagine everyone is queueing normally for a MacDonald when Elisha decided to bring his friend, Kenneth into the queue.

How do i append "Kenneth" to "Main":"Elisha" so that when I print dict['Main'] it will return the following expected output:

Expected Output: [Tammy, Elisha, Kenneth, Julius ]

If Elisha decided to bring in another friend, "Elisha": ["Nicole"]. Then the expected output would be:

Expected Output: [ Tammy, Elisha, Kenneth, Nicole, Julius ]

I tried googling for append, however append doesn't work for dictionary but only on list.

I tried:

dict['Main'].value("Elisha").append("Kenneth")

but it returned error.

Answer 1

You can recursively print the queue How it works:

1. Make a empty queue
2. Start from the first person in the Main queue
3. Add that person to the empty queue mentioned in 1
4. Check if there is any friend of that person, if so
5. Add them in the queue mentioned in 1, and check their friends also if exists

d = {"Main":["Tammy","Elisha","Julius"],

        "Elisha": ["Kenneth"]
       }

def get_flattened_queue(data, key, flattened_queue):
    members = data[key]
    for each_member in members:
        flattened_queue.append(each_member)
        if each_member in data.keys():
            get_flattened_queue(data, each_member, flattened_queue)
    return flattened_queue

flattened_queue = []
get_flattened_queue(d, 'Main', flattened_queue)

print(flattened_queue)

['Tammy', 'Elisha', 'Kenneth', 'Julius']

Now suppose Elisa brings Nicole

d = {"Main":["Tammy","Elisha","Julius"],

        "Elisha": ["Kenneth"]
       }

def get_flattened_queue(data, key, flattened_queue):
    members = data[key]
    for each_member in members:
        flattened_queue.append(each_member)
        if each_member in data.keys():
            get_flattened_queue(data, each_member, flattened_queue)
    return flattened_queue

# Here she brings Nicole
d['Elisha'].append('Nicole')

#{"Main":["Tammy","Elisha","Julius"],
#        "Elisha": ["Kenneth", "Nicole"]
#       }

flattened_queue = []
get_flattened_queue(d, 'Main', flattened_queue)

print(flattened_queue)

['Tammy', 'Elisha', 'Kenneth', 'Nicole', 'Julius']

---

d = {"Main":["Tammy","Elisha","Julius"],

        "Elisha": ["Kenneth"]
       }

def get_flattened_queue(data, key, flattened_queue):
    members = data[key]
    for each_member in members:
        flattened_queue.append(each_member)
        if each_member in data.keys():
            get_flattened_queue(data, each_member, flattened_queue)
    return flattened_queue

# Here she brings Nicole
d['Elisha'].append('Nicole')

#{"Main":["Tammy","Elisha","Julius"],
#        "Elisha": ["Kenneth", "Nicole"]
#       }

# Nicole brings Epsi95
d['Nicole'] = ['Epsi95']

flattened_queue = []
get_flattened_queue(d, 'Main', flattened_queue)

print(flattened_queue)

{'Main': ['Tammy', 'Elisha', 'Julius'],
 'Elisha': ['Kenneth', 'Nicole'],
 'Nicole': ['Epsi95']}


['Tammy', 'Elisha', 'Kenneth', 'Nicole', 'Epsi95', 'Julius']