Extract the duplicate values from dictionary

extract_dict.py

from collections import Counter
my_dict = {'F': 200, 'G': 500, 'D': 100, 'E': 400, 'B': 200, 'C': 300, 'A': 500}

# duplicate values list
dup_list = [k for k, v in Counter(my_dict.values()).items() if v > 1] # [200, 500]

print({k: v for k, v in my_dict.items() if v in dup_list}) # {'F': 200, 'G': 500, 'B': 200, 'A': 500}