I am looking to create calculate the full set of dependencies of my dictionary data in python using recursion

Question

The program should use this data to calculate the full set of dependencies. For example, looking at B, we see it directly depends on C and E. C in turn relies on G, E relies on F, and F relies on H. This means that B ultimately relies on C, E, F, G, and H.

input_data ={
    "A":["B","C"],
    "B":["C","E"],
    "C":["G"],
    "D":["A","F"],
    "E":["F"],
    "F":["H"]
}

output will be the reference of for all of dependent values.

output ={
    "A":["B","C","E","F","G","H"],
    "B":["C","E","F","G","H"],
    "C":["G"],
    "D":["A","B","C","E","F","G","H"],
    "E":["F","H"],
    "F":["H"]
}

If possible I want try it with recursion

I tried something like this

import copy
output = copy.deepcopy(input_data)

def rec_update(key, values):
    for value in values:
        if not input_data .get(value):
            if not value in output[key]:
                output[key].append(value)
        else:
            rec_update(value, input_data .get(value))

for key, values in input_data .items():
    rec_update(key, values)

Answer 1

Here is my suggestion. Firstly we create a function that iterates through the input_data for x, adding new child items. It stops when no new child items are found. Then we apply this function on all keys of input_data:

input_data ={
    "A":["B","C"],
    "B":["C","E"],
    "C":["G"],
    "D":["A","F"],
    "E":["F"],
    "F":["H"]
}

def f(x):
    res=[]
    new=input_data[x]
    while new!=[]:
        res.extend([i for i in new if i not in res])
        temp=[]
        for i in res:
            if input_data.get(i):
                temp.extend(input_data.get(i))
        new=[k for k in temp if k not in res]
    return res

output={i:f(i) for i in input_data}

print(output)

Result:

{'A': ['B', 'C', 'E', 'G', 'F', 'H'], 'B': ['C', 'E', 'G', 'F', 'H'], 'C': ['G'], 'D': ['A', 'F', 'B', 'C', 'H', 'E', 'G'], 'E': ['F', 'H'], 'F': ['H']}