How do I return a dictionary of values from a list?

Question

How can I edit the commented-off piece of code so that it returns a dictionary of the duplicate numbers rather than returning "{}"?

listOfElems = ["a", "c", "c"]

def checkIfDuplicates_3(listOfElems):
  duplicates = {}
  for x in listOfElems:
#    duplicates = ??
    if listOfElems.count(x) > 1:
      return duplicates
  return duplicates

#test 
test = [listOfElems]

for t in test:
  output = checkIfDuplicates_3(t)
  print("The duplicate in", t, "is", output)

Answer 1

Here's a solution.

If there is more than one of the element in the list, listOfElems.count(x) > 1, and our list of duplicates doesn't contain the element already, duplicates.count(x) == 0, then we can add the element to the list of duplicates.

listOfElems = ["a", "c", "c"]


def checkIfDuplicates_3(listOfElems):
    duplicates = []
    for x in listOfElems:
        if listOfElems.count(x) > 1 and duplicates.count(x) == 0:
            duplicates.append(x)
    return duplicates


# test
test = [listOfElems]

for t in test:
    output = checkIfDuplicates_3(t)
    print("The duplicate in", t, "is", output)