If I have an arbitrary amount of elements, each with a specified set of values, what can I do to get all possible combinations with a value from each element’s set?
For example, let’s say I have:
elems = {"A": (0, 1), "B": (-1, -5)}What can I do to get the following?
({"A": 0, "B": -1}, {"A": 0, "B": -5}, {"A": 1, "B": -1}, {"A": 1, "B": -5})Input/output don’t need to use dicts, but I figured that’s the easiest way to represent it. Assume dict order matters.
I would like to know a way that:
- Does not assume there are just 2 elements like in the example.
- Does not assume the sets for all elements have an equal length.
It is somewhat like listing all inputs for a truth table.
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Answer
You can use a nested list/dictionary comprehension, using itertools.product to generate all combinations of the values, and then ziping each result tuple from that to the keys to generate the key/value pairs to make up each dictionary result. Here’s an example using a slightly more complicated version of your data:
import itertoolselems = {"A": (0, 1), "B": (-1, -5), "C": (1, 2, 3) }keys = elems.keys()res = [dict(zip(keys, p)) for p in itertools.product(*elems.values())]Output:
[ {'A': 0, 'B': -1, 'C': 1}, {'A': 0, 'B': -1, 'C': 2}, {'A': 0, 'B': -1, 'C': 3}, {'A': 0, 'B': -5, 'C': 1}, {'A': 0, 'B': -5, 'C': 2}, {'A': 0, 'B': -5, 'C': 3}, {'A': 1, 'B': -1, 'C': 1}, {'A': 1, 'B': -1, 'C': 2}, {'A': 1, 'B': -1, 'C': 3}, {'A': 1, 'B': -5, 'C': 1}, {'A': 1, 'B': -5, 'C': 2}, {'A': 1, 'B': -5, 'C': 3}]