How do I generate a dictionary with a specified number of keys and a random number of values per key?

Question

Say I specified the number of keys to be 5 (so that the keys are 0,1,2,3, and 4 etc.) and I wanted the number of values to be random per key, where each value is 0,1,2,3, or 4, with no repeated values in each key. I am trying to make a Random Complete Graph if that means anything to you. Ex of output:

dict = { "0": ["3"],
         "1": ["4"],
         "2": ["3","4"],
         "3": ["0","2"],
         "4": ["1","2"]
       }

Try writing some code. That should do it. – John Zwinck May 14 '17 at 04:28 — John Zwinck, May 14 '17 at 04:28
look for `random.sample` for no repeated values – mtkilic May 14 '17 at 04:37 — mtkilic, May 14 '17 at 04:37

score 2 · Answer 1 · answered May 14 '17 at 05:00

2

import random

number_of_nodes = 5
graph = dict()

for i in range(number_of_nodes):
    graph[i] = random.sample(range(0, number_of_nodes), random.randint(0, number_of_nodes))

answered May 14 '17 at 05:00

mohammad

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That's an impressive more efficient way to code than my answer!! Thanks for sharing – Vinícius Figueiredo May 14 '17 at 05:03
Thank you very much, that is straight forward – Jason M Gray May 14 '17 at 05:23

score 0 · Answer 2 · edited May 23 '17 at 10:31

You can try creating the dictionary from two lists, keys, which are your integers from 0 to 4, and values, which are random picks (random.choice(seq)) from a list containing every possible combination(of any length) of your numbers, and that's exactly what the initials for loops are there(check this answer). Notice the final dictionary's values are tuples, it's not hard to output them the way you need changing the code from here on. Also notice that since we already are importing itertools the construction of the dictionary can be coded using dict(itertools.izip(keys,values)), and that seems to be a more economical approach in a big lists scenario.

import random
import itertools

n = 5
keys = range(n)
numbers = [0,1,2,3,4] #or simply numbers = range(n), if that's what you need
values = []
possibleValues = []

for L in range(0, len(numbers)+1):
  for subset in itertools.combinations(numbers, L):
    possibleValues.append(subset)

for i in range(len(numbers)):
    values.append(random.choice(possibleValues))

dictionary = dict(zip(keys, values))

How do I generate a dictionary with a specified number of keys and a random number of values per key?

2 Answers2