How to group intersecting Shapely geometric objects in a list of tuples

Keep a dict of objects mapped to A,B and C, a set of matched objects and only add the single elements that have no matches after we get to a new letter if they are not in our matched set as all possible combinations will have been tested:

from shapely.geometry import box
from itertools import combinations

codes = ["A", "B", "C"]
d = dict(zip(codes, data))
prev = codes[0]
matched, out = set(), []
for p1, p2 in combinations(codes, 2):
    if d[p1].intersects(d[p2]):
        out.append((p1, p2))
        matched.update([p1, p2])
    # when p1 is a new letter, we have tried all combs for that prev
    # if prev is not in matched it did not intersect any other so
   # add it as a single tuple and add to matched to avoid dupes
    elif p1 != prev and prev not in matched:
        out.append(tuple(prev,))
        matched.add(prev)
    prev = p1
# catch the last letter
if p2 not in matched:
    out.append(tuple(p2,))
print(out)
[('A', 'C'), ('B',)]